NEWS
author wenzelm
Fri Feb 03 23:12:28 2006 +0100 (2006-02-03 ago)
changeset 18921 f47c46d7d654
parent 18910 50a27d7c8951
child 18979 f0873dcc880f
permissions -rw-r--r--
canonical member/insert/merge;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle release
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory syntax: the header format ``theory A = B + C:'' has been
    10 discontinued in favour of ``theory A imports B C begin''.  Use isatool
    11 fixheaders to convert existing theory files.  INCOMPATIBILITY.
    12 
    13 * Theory syntax: the old non-Isar theory file format has been
    14 discontinued altogether.  Note that ML proof scripts may still be used
    15 with Isar theories; migration is usually quite simple with the ML
    16 function use_legacy_bindings.  INCOMPATIBILITY.
    17 
    18 * Legacy goal package: reduced interface to the bare minimum required
    19 to keep existing proof scripts running.  Most other user-level
    20 functions are now part of the OldGoals structure, which is *not* open
    21 by default (consider isatool expandshort before open OldGoals).
    22 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
    23 these tend to cause confusion about the actual goal (!) context being
    24 used here, which is not necessarily the same as the_context().
    25 
    26 * Command 'find_theorems': support "*" wildcard in "name:" criterion.
    27 
    28 
    29 *** Document preparation ***
    30 
    31 * Added antiquotations @{ML_type text} and @{ML_struct text} which
    32 check the given source text as ML type/structure, printing verbatim.
    33 
    34 
    35 *** Pure ***
    36 
    37 * Isar: improper proof element 'guess' is like 'obtain', but derives
    38 the obtained context from the course of reasoning!  For example:
    39 
    40   assume "EX x y. A x & B y"   -- "any previous fact"
    41   then guess x and y by clarify
    42 
    43 This technique is potentially adventurous, depending on the facts and
    44 proof tools being involved here.
    45 
    46 * Isar: known facts from the proof context may be specified as literal
    47 propositions, using ASCII back-quote syntax.  This works wherever
    48 named facts used to be allowed so far, in proof commands, proof
    49 methods, attributes etc.  Literal facts are retrieved from the context
    50 according to unification of type and term parameters.  For example,
    51 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
    52 theorems in the current context, then these are valid literal facts:
    53 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
    54 
    55 There is also a proof method "fact" which does the same composition
    56 for explicit goal states, e.g. the following proof texts coincide with
    57 certain special cases of literal facts:
    58 
    59   have "A" by fact                 ==  note `A`
    60   have "A ==> B" by fact           ==  note `A ==> B`
    61   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
    62   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
    63 
    64 * Isar: 'def' now admits simultaneous definitions, e.g.:
    65 
    66   def x == "t" and y == "u"
    67 
    68 * Isar: added command 'unfolding', which is structurally similar to
    69 'using', but affects both the goal state and facts by unfolding given
    70 rewrite rules.  Thus many occurrences of the 'unfold' method or
    71 'unfolded' attribute may be replaced by first-class proof text.
    72 
    73 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
    74 and command 'unfolding' now all support object-level equalities
    75 (potentially conditional).  The underlying notion of rewrite rule is
    76 analogous to the 'rule_format' attribute, but *not* that of the
    77 Simplifier (which is usually more generous).
    78 
    79 * Isar: the conclusion of a long theorem statement is now either
    80 'shows' (a simultaneous conjunction, as before), or 'obtains'
    81 (essentially a disjunction of cases with local parameters and
    82 assumptions).  The latter allows to express general elimination rules
    83 adequately; in this notation common elimination rules look like this:
    84 
    85   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
    86     assumes "EX x. P x"
    87     obtains x where "P x"
    88 
    89   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
    90     assumes "A & B"
    91     obtains A and B
    92 
    93   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
    94     assumes "A | B"
    95     obtains
    96       A
    97     | B
    98 
    99 The subsequent classical rules even refer to the formal "thesis"
   100 explicitly:
   101 
   102   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   103     obtains "~ thesis"
   104 
   105   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   106     obtains "thesis ==> something"
   107 
   108 The actual proof of an 'obtains' statement is analogous to that of the
   109 Isar proof element 'obtain', only that there may be several cases.
   110 Optional case names may be specified in parentheses; these will be
   111 available both in the present proof and as annotations in the
   112 resulting rule, for later use with the 'cases' method (cf. attribute
   113 case_names).
   114 
   115 * Isar: 'obtain' takes an optional case name for the local context
   116 introduction rule (default "that").
   117 
   118 * Provers/induct: improved internal context management to support
   119 local fixes and defines on-the-fly.  Thus explicit meta-level
   120 connectives !! and ==> are rarely required anymore in inductive goals
   121 (using object-logic connectives for this purpose has been long
   122 obsolete anyway).  The subsequent proof patterns illustrate advanced
   123 techniques of natural induction; general datatypes and inductive sets
   124 work analogously (see also src/HOL/Lambda for realistic examples).
   125 
   126 (1) This is how to ``strengthen'' an inductive goal wrt. certain
   127 parameters:
   128 
   129   lemma
   130     fixes n :: nat and x :: 'a
   131     assumes a: "A n x"
   132     shows "P n x"
   133     using a                     -- {* make induct insert fact a *}
   134   proof (induct n fixing: x)    -- {* generalize goal to "!!x. A n x ==> P n x" *}
   135     case 0
   136     show ?case sorry
   137   next
   138     case (Suc n)
   139     note `!!x. A n x ==> P n x` -- {* induction hypothesis, according to induction rule *}
   140     note `A (Suc n) x`          -- {* induction premise, stemming from fact a *}
   141     show ?case sorry
   142   qed
   143 
   144 (2) This is how to perform induction over ``expressions of a certain
   145 form'', using a locally defined inductive parameter n == "a x"
   146 together with strengthening (the latter is usually required to get
   147 sufficiently flexible induction hypotheses):
   148 
   149   lemma
   150     fixes a :: "'a => nat"
   151     assumes a: "A (a x)"
   152     shows "P (a x)"
   153     using a
   154   proof (induct n == "a x" fixing: x)
   155     ...
   156 
   157 See also HOL/Isar_examples/Puzzle.thy for an application of the this
   158 particular technique.
   159 
   160 (3) This is how to perform existential reasoning ('obtains' or
   161 'obtain') by induction, while avoiding explicit object-logic
   162 encodings:
   163 
   164   lemma
   165     fixes n :: nat
   166     obtains x :: 'a where "P n x" and "Q n x"
   167   proof (induct n fixing: thesis)
   168     case 0
   169     obtain x where "P 0 x" and "Q 0 x" sorry
   170     then show thesis by (rule 0)
   171   next
   172     case (Suc n)
   173     obtain x where "P n x" and "Q n x" by (rule Suc.hyps)
   174     obtain x where "P (Suc n) x" and "Q (Suc n) x" sorry
   175     then show thesis by (rule Suc.prems)
   176   qed
   177 
   178 Here the 'fixing: thesis' specification essentially modifies the scope
   179 of the formal thesis parameter, in order to the get the whole
   180 existence statement through the induction as expected.
   181 
   182 * Provers/induct: mutual induction rules are now specified as a list
   183 of rule sharing the same induction cases.  HOL packages usually
   184 provide foo_bar.inducts for mutually defined items foo and bar
   185 (e.g. inductive sets or datatypes).  INCOMPATIBILITY, users need to
   186 specify mutual induction rules differently, i.e. like this:
   187 
   188   (induct rule: foo_bar.inducts)
   189   (induct set: foo bar)
   190   (induct type: foo bar)
   191 
   192 The ML function ProjectRule.projections turns old-style rules into the
   193 new format.
   194 
   195 * Provers/induct: improved handling of simultaneous goals.  Instead of
   196 introducing object-level conjunction, the statement is now split into
   197 several conclusions, while the corresponding symbolic cases are
   198 nested accordingly.  INCOMPATIBILITY, proofs need to be structured
   199 explicitly.  For example:
   200 
   201   lemma
   202     fixes n :: nat
   203     shows "P n" and "Q n"
   204   proof (induct n)
   205     case 0 case 1
   206     show "P 0" sorry
   207   next
   208     case 0 case 2
   209     show "Q 0" sorry
   210   next
   211     case (Suc n) case 1
   212     note `P n` and `Q n`
   213     show "P (Suc n)" sorry
   214   next
   215     case (Suc n) case 2
   216     note `P n` and `Q n`
   217     show "Q (Suc n)" sorry
   218   qed
   219 
   220 The split into subcases may be deferred as follows -- this is
   221 particularly relevant for goal statements with local premises.
   222 
   223   lemma
   224     fixes n :: nat
   225     shows "A n ==> P n" and "B n ==> Q n"
   226   proof (induct n)
   227     case 0
   228     {
   229       case 1
   230       note `A 0`
   231       show "P 0" sorry
   232     next
   233       case 2
   234       note `B 0`
   235       show "Q 0" sorry
   236     }
   237   next
   238     case (Suc n)
   239     note `A n ==> P n` and `B n ==> Q n`
   240     {
   241       case 1
   242       note `A (Suc n)`
   243       show "P (Suc n)" sorry
   244     next
   245       case 2
   246       note `B (Suc n)`
   247       show "Q (Suc n)" sorry
   248     }
   249   qed
   250 
   251 If simultaneous goals are to be used with mutual rules, the statement
   252 needs to be structured carefully as a two-level conjunction, using
   253 lists of propositions separated by 'and':
   254 
   255   lemma
   256     shows "a : A ==> P1 a"
   257           "a : A ==> P2 a"
   258       and "b : B ==> Q1 b"
   259           "b : B ==> Q2 b"
   260           "b : B ==> Q3 b"
   261   proof (induct set: A B)
   262 
   263 * Provers/induct: support coinduction as well.  See
   264 src/HOL/Library/Coinductive_List.thy for various examples.
   265 
   266 * Simplifier: by default the simplifier trace only shows top level rewrites
   267 now. That is, trace_simp_depth_limit is set to 1 by default. Thus there is
   268 less danger of being flooded by the trace. The trace indicates where parts
   269 have been suppressed.
   270   
   271 * Provers/classical: removed obsolete classical version of elim_format
   272 attribute; classical elim/dest rules are now treated uniformly when
   273 manipulating the claset.
   274 
   275 * Provers/classical: stricter checks to ensure that supplied intro,
   276 dest and elim rules are well-formed; dest and elim rules must have at
   277 least one premise.
   278 
   279 * Provers/classical: attributes dest/elim/intro take an optional
   280 weight argument for the rule (just as the Pure versions).  Weights are
   281 ignored by automated tools, but determine the search order of single
   282 rule steps.
   283 
   284 * Syntax: input syntax now supports dummy variable binding "%_. b",
   285 where the body does not mention the bound variable.  Note that dummy
   286 patterns implicitly depend on their context of bounds, which makes
   287 "{_. _}" match any set comprehension as expected.  Potential
   288 INCOMPATIBILITY -- parse translations need to cope with syntactic
   289 constant "_idtdummy" in the binding position.
   290 
   291 * Syntax: removed obsolete syntactic constant "_K" and its associated
   292 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   293 for example "A -> B" => "Pi A (%_. B)".
   294 
   295 
   296 *** HOL ***
   297 
   298 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
   299 'rule' method.
   300 
   301 * Alternative iff syntax "A <-> B" for equality on bool (with priority
   302 25 like -->); output depends on the "iff" print_mode, the default is
   303 "A = B" (with priority 50).
   304 
   305 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
   306 
   307 * In the context of the assumption "~(s = t)" the Simplifier rewrites
   308 "t = s" to False (by simproc "neq_simproc").  For backward
   309 compatibility this can be disabled by ML "reset use_neq_simproc".
   310 
   311 * Tactics 'sat' and 'satx' reimplemented, several improvements: goals
   312 no longer need to be stated as "<prems> ==> False", equivalences (i.e.
   313 "=" on type bool) are handled, variable names of the form "lit_<n>"
   314 are no longer reserved, significant speedup.
   315 
   316 * inductive and datatype: provide projections of mutual rules, bundled
   317 as foo_bar.inducts;
   318 
   319 * Library: added theory Coinductive_List of potentially infinite lists
   320 as greatest fixed-point.
   321 
   322 
   323 *** ML ***
   324 
   325 * Pure/library:
   326 
   327   val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
   328   val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
   329 
   330 The semantics of "burrow" is: "take a function with *simulatanously*
   331 transforms a list of value, and apply it *simulatanously* to a list of
   332 list of values of the appropriate type". Confer this with "map" which
   333 would *not* apply its argument function simulatanously but in
   334 sequence. "fold_burrow" has an additional context.
   335 
   336 Both actually avoid the usage of "unflat" since they hide away
   337 "unflat" from the user.
   338 
   339 * Pure/library: functions map2 and fold2 with curried syntax for
   340 simultanous mapping and folding:
   341 
   342     val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   343     val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   344 
   345 * Pure/library: indexed lists - some functions in the Isabelle library
   346 treating lists over 'a as finite mappings from [0...n] to 'a have been
   347 given more convenient names and signatures reminiscent of similar
   348 functions for alists, tables, etc:
   349 
   350   val nth: 'a list -> int -> 'a 
   351   val nth_update: int * 'a -> 'a list -> 'a list
   352   val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
   353   val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
   354 
   355 Note that fold_index starts counting at index 0, not 1 like foldln
   356 used to.
   357 
   358 * Pure/General: name_mangler.ML provides a functor for generic name
   359 mangling (bijective mapping from any expression values to strings).
   360 
   361 * Pure/General: rat.ML implements rational numbers.
   362 
   363 * Pure: datatype Context.generic joins theory/Proof.context and
   364 provides some facilities for code that works in either kind of
   365 context, notably GenericDataFun for uniform theory and proof data.
   366 
   367 * Pure: 'advanced' translation functions (parse_translation etc.) now
   368 use Context.generic instead of just theory.
   369 
   370 * Pure: simplified internal attribute type, which is now always
   371 Context.generic * thm -> Context.generic * thm.  Global (theory)
   372 vs. local (Proof.context) attributes have been discontinued, while
   373 minimizing code duplication.  Thm.rule_attribute and
   374 Thm.declaration_attribute build canonical attributes; see also
   375 structure Context for further operations on Context.generic.
   376 
   377 INCOMPATIBILITY, need to adapt attribute type declarations and
   378 definitions.  Hint: make proper use of GenericDataFun and generic
   379 Args/Attrib syntax instead of working around legacy code.
   380 
   381 * Pure: several functions of signature "... -> theory -> theory * ..."
   382 have been reoriented to "... -> theory -> ... * theory" in order to
   383 allow natural usage in combination with the ||>, ||>>, |-> and
   384 fold_map combinators.
   385 
   386 * Pure: primitive rule lift_rule now takes goal cterm instead of an
   387 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
   388 achieve the old behaviour.
   389 
   390 * Pure: the "Goal" constant is now called "prop", supporting a
   391 slightly more general idea of ``protecting'' meta-level rule
   392 statements.
   393 
   394 * Pure: structure Goal provides simple interfaces for
   395 init/conclude/finish and tactical prove operations (replacing former
   396 Tactic.prove).  Note that OldGoals.prove_goalw_cterm has long been
   397 obsolete, it is ill-behaved in a local proof context (e.g. with local
   398 fixes/assumes or in a locale context).
   399 
   400 * Isar: simplified treatment of user-level errors, using exception
   401 ERROR of string uniformly.  Function error now merely raises ERROR,
   402 without any side effect on output channels.  The Isar toplevel takes
   403 care of proper display of ERROR exceptions.  ML code may use plain
   404 handle/can/try; cat_error may be used to concatenate errors like this:
   405 
   406   ... handle ERROR msg => cat_error msg "..."
   407 
   408 Toplevel ML code (run directly or through the Isar toplevel) may be
   409 embedded into the Isar toplevel with exception display/debug like
   410 this:
   411 
   412   Isar.toplevel (fn () => ...)
   413 
   414 INCOMPATIBILITY, removed special transform_error facilities, removed
   415 obsolete variants of user-level exceptions (ERROR_MESSAGE,
   416 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
   417 -- use plain ERROR instead.
   418 
   419 * Isar: theory setup now has type (theory -> theory), instead of a
   420 list.  INCOMPATIBILITY, may use #> to compose setup functions.
   421 
   422 * Isar: installed ML toplevel pretty printer for type Proof.context,
   423 subject to ProofContext.debug/verbose flags.
   424 
   425 * Isar: Toplevel.theory_to_proof admits transactions that modify the
   426 theory before entering a proof state.  Transactions now always see a
   427 quasi-functional intermediate checkpoint, both in interactive and
   428 batch mode.
   429 
   430 * Simplifier: the simpset of a running simplification process now
   431 contains a proof context (cf. Simplifier.the_context), which is the
   432 very context that the initial simpset has been retrieved from (by
   433 simpset_of/local_simpset_of).  Consequently, all plug-in components
   434 (solver, looper etc.) may depend on arbitrary proof data.
   435 
   436 * Simplifier.inherit_context inherits the proof context (plus the
   437 local bounds) of the current simplification process; any simproc
   438 etc. that calls the Simplifier recursively should do this!  Removed
   439 former Simplifier.inherit_bounds, which is already included here --
   440 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
   441 specify an explicit context using Simplifier.context/theory_context.
   442 
   443 * Simplifier/Classical Reasoner: more abstract interfaces
   444 change_simpset/claset for modifying the simpset/claset reference of a
   445 theory; raw versions simpset/claset_ref etc. have been discontinued --
   446 INCOMPATIBILITY.
   447 
   448 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
   449 "Trueprop" etc.
   450 
   451 
   452 
   453 New in Isabelle2005 (October 2005)
   454 ----------------------------------
   455 
   456 *** General ***
   457 
   458 * Theory headers: the new header syntax for Isar theories is
   459 
   460   theory <name>
   461   imports <theory1> ... <theoryN>
   462   uses <file1> ... <fileM>
   463   begin
   464 
   465 where the 'uses' part is optional.  The previous syntax
   466 
   467   theory <name> = <theory1> + ... + <theoryN>:
   468 
   469 will disappear in the next release.  Use isatool fixheaders to convert
   470 existing theory files.  Note that there is no change in ancient
   471 non-Isar theories now, but these will disappear soon.
   472 
   473 * Theory loader: parent theories can now also be referred to via
   474 relative and absolute paths.
   475 
   476 * Command 'find_theorems' searches for a list of criteria instead of a
   477 list of constants. Known criteria are: intro, elim, dest, name:string,
   478 simp:term, and any term. Criteria can be preceded by '-' to select
   479 theorems that do not match. Intro, elim, dest select theorems that
   480 match the current goal, name:s selects theorems whose fully qualified
   481 name contain s, and simp:term selects all simplification rules whose
   482 lhs match term.  Any other term is interpreted as pattern and selects
   483 all theorems matching the pattern. Available in ProofGeneral under
   484 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
   485 
   486   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
   487 
   488 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
   489 matching the current goal as introduction rule and not having "HOL."
   490 in their name (i.e. not being defined in theory HOL).
   491 
   492 * Command 'thms_containing' has been discontinued in favour of
   493 'find_theorems'; INCOMPATIBILITY.
   494 
   495 * Communication with Proof General is now 8bit clean, which means that
   496 Unicode text in UTF-8 encoding may be used within theory texts (both
   497 formal and informal parts).  Cf. option -U of the Isabelle Proof
   498 General interface.  Here are some simple examples (cf. src/HOL/ex):
   499 
   500   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
   501   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
   502 
   503 * Improved efficiency of the Simplifier and, to a lesser degree, the
   504 Classical Reasoner.  Typical big applications run around 2 times
   505 faster.
   506 
   507 
   508 *** Document preparation ***
   509 
   510 * Commands 'display_drafts' and 'print_drafts' perform simple output
   511 of raw sources.  Only those symbols that do not require additional
   512 LaTeX packages (depending on comments in isabellesym.sty) are
   513 displayed properly, everything else is left verbatim.  isatool display
   514 and isatool print are used as front ends (these are subject to the
   515 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
   516 
   517 * Command tags control specific markup of certain regions of text,
   518 notably folding and hiding.  Predefined tags include "theory" (for
   519 theory begin and end), "proof" for proof commands, and "ML" for
   520 commands involving ML code; the additional tags "visible" and
   521 "invisible" are unused by default.  Users may give explicit tag
   522 specifications in the text, e.g. ''by %invisible (auto)''.  The
   523 interpretation of tags is determined by the LaTeX job during document
   524 preparation: see option -V of isatool usedir, or options -n and -t of
   525 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
   526 \isadroptag.
   527 
   528 Several document versions may be produced at the same time via isatool
   529 usedir (the generated index.html will link all of them).  Typical
   530 specifications include ''-V document=theory,proof,ML'' to present
   531 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
   532 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
   533 these parts without any formal replacement text.  The Isabelle site
   534 default settings produce ''document'' and ''outline'' versions as
   535 specified above.
   536 
   537 * Several new antiquotations:
   538 
   539   @{term_type term} prints a term with its type annotated;
   540 
   541   @{typeof term} prints the type of a term;
   542 
   543   @{const const} is the same as @{term const}, but checks that the
   544   argument is a known logical constant;
   545 
   546   @{term_style style term} and @{thm_style style thm} print a term or
   547   theorem applying a "style" to it
   548 
   549   @{ML text}
   550 
   551 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
   552 definitions, equations, inequations etc., 'concl' printing only the
   553 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
   554 to print the specified premise.  TermStyle.add_style provides an ML
   555 interface for introducing further styles.  See also the "LaTeX Sugar"
   556 document practical applications.  The ML antiquotation prints
   557 type-checked ML expressions verbatim.
   558 
   559 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
   560 and 'text' support optional locale specification '(in loc)', which
   561 specifies the default context for interpreting antiquotations.  For
   562 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
   563 
   564 * Option 'locale=NAME' of antiquotations specifies an alternative
   565 context interpreting the subsequent argument.  For example: @{thm
   566 [locale=lattice] inf_assoc}.
   567 
   568 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
   569 a proof context.
   570 
   571 * Proper output of antiquotations for theory commands involving a
   572 proof context (such as 'locale' or 'theorem (in loc) ...').
   573 
   574 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
   575 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
   576 
   577 * isatool usedir: new option -C (default true) controls whether option
   578 -D should include a copy of the original document directory; -C false
   579 prevents unwanted effects such as copying of administrative CVS data.
   580 
   581 
   582 *** Pure ***
   583 
   584 * Considerably improved version of 'constdefs' command.  Now performs
   585 automatic type-inference of declared constants; additional support for
   586 local structure declarations (cf. locales and HOL records), see also
   587 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
   588 sequential dependencies of definitions within a single 'constdefs'
   589 section; moreover, the declared name needs to be an identifier.  If
   590 all fails, consider to fall back on 'consts' and 'defs' separately.
   591 
   592 * Improved indexed syntax and implicit structures.  First of all,
   593 indexed syntax provides a notational device for subscripted
   594 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
   595 expressions.  Secondly, in a local context with structure
   596 declarations, number indexes \<^sub>n or the empty index (default
   597 number 1) refer to a certain fixed variable implicitly; option
   598 show_structs controls printing of implicit structures.  Typical
   599 applications of these concepts involve record types and locales.
   600 
   601 * New command 'no_syntax' removes grammar declarations (and
   602 translations) resulting from the given syntax specification, which is
   603 interpreted in the same manner as for the 'syntax' command.
   604 
   605 * 'Advanced' translation functions (parse_translation etc.) may depend
   606 on the signature of the theory context being presently used for
   607 parsing/printing, see also isar-ref manual.
   608 
   609 * Improved 'oracle' command provides a type-safe interface to turn an
   610 ML expression of type theory -> T -> term into a primitive rule of
   611 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
   612 is already included here); see also FOL/ex/IffExample.thy;
   613 INCOMPATIBILITY.
   614 
   615 * axclass: name space prefix for class "c" is now "c_class" (was "c"
   616 before); "cI" is no longer bound, use "c.intro" instead.
   617 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
   618 axclasses vs. locales.
   619 
   620 * Improved internal renaming of symbolic identifiers -- attach primes
   621 instead of base 26 numbers.
   622 
   623 * New flag show_question_marks controls printing of leading question
   624 marks in schematic variable names.
   625 
   626 * In schematic variable names, *any* symbol following \<^isub> or
   627 \<^isup> is now treated as part of the base name.  For example, the
   628 following works without printing of awkward ".0" indexes:
   629 
   630   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
   631     by simp
   632 
   633 * Inner syntax includes (*(*nested*) comments*).
   634 
   635 * Pretty printer now supports unbreakable blocks, specified in mixfix
   636 annotations as "(00...)".
   637 
   638 * Clear separation of logical types and nonterminals, where the latter
   639 may only occur in 'syntax' specifications or type abbreviations.
   640 Before that distinction was only partially implemented via type class
   641 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
   642 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
   643 exotic syntax specifications may require further adaption
   644 (e.g. Cube/Cube.thy).
   645 
   646 * Removed obsolete type class "logic", use the top sort {} instead.
   647 Note that non-logical types should be declared as 'nonterminals'
   648 rather than 'types'.  INCOMPATIBILITY for new object-logic
   649 specifications.
   650 
   651 * Attributes 'induct' and 'cases': type or set names may now be
   652 locally fixed variables as well.
   653 
   654 * Simplifier: can now control the depth to which conditional rewriting
   655 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
   656 Limit.
   657 
   658 * Simplifier: simplification procedures may now take the current
   659 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
   660 interface), which is very useful for calling the Simplifier
   661 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
   662 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
   663 low-level mk_simproc no longer applies Logic.varify internally, to
   664 allow for use in a context of fixed variables.
   665 
   666 * thin_tac now works even if the assumption being deleted contains !!
   667 or ==>.  More generally, erule now works even if the major premise of
   668 the elimination rule contains !! or ==>.
   669 
   670 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
   671 
   672 * Reorganized bootstrapping of the Pure theories; CPure is now derived
   673 from Pure, which contains all common declarations already.  Both
   674 theories are defined via plain Isabelle/Isar .thy files.
   675 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
   676 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
   677 use isatool fixcpure to adapt your theory and ML sources.
   678 
   679 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
   680 selections of theorems in named facts via index ranges.
   681 
   682 * 'print_theorems': in theory mode, really print the difference
   683 wrt. the last state (works for interactive theory development only),
   684 in proof mode print all local facts (cf. 'print_facts');
   685 
   686 * 'hide': option '(open)' hides only base names.
   687 
   688 * More efficient treatment of intermediate checkpoints in interactive
   689 theory development.
   690 
   691 * Code generator is now invoked via code_module (incremental code
   692 generation) and code_library (modular code generation, ML structures
   693 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
   694 must be quoted when used as identifiers.
   695 
   696 * New 'value' command for reading, evaluating and printing terms using
   697 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
   698 quoted when used as identifier.
   699 
   700 
   701 *** Locales ***
   702 
   703 * New commands for the interpretation of locale expressions in
   704 theories (1), locales (2) and proof contexts (3).  These generate
   705 proof obligations from the expression specification.  After the
   706 obligations have been discharged, theorems of the expression are added
   707 to the theory, target locale or proof context.  The synopsis of the
   708 commands is a follows:
   709 
   710   (1) interpretation expr inst
   711   (2) interpretation target < expr
   712   (3) interpret expr inst
   713 
   714 Interpretation in theories and proof contexts require a parameter
   715 instantiation of terms from the current context.  This is applied to
   716 specifications and theorems of the interpreted expression.
   717 Interpretation in locales only permits parameter renaming through the
   718 locale expression.  Interpretation is smart in that interpretations
   719 that are active already do not occur in proof obligations, neither are
   720 instantiated theorems stored in duplicate.  Use 'print_interps' to
   721 inspect active interpretations of a particular locale.  For details,
   722 see the Isar Reference manual.  Examples can be found in
   723 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
   724 
   725 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
   726 'interpret' instead.
   727 
   728 * New context element 'constrains' for adding type constraints to
   729 parameters.
   730 
   731 * Context expressions: renaming of parameters with syntax
   732 redeclaration.
   733 
   734 * Locale declaration: 'includes' disallowed.
   735 
   736 * Proper static binding of attribute syntax -- i.e. types / terms /
   737 facts mentioned as arguments are always those of the locale definition
   738 context, independently of the context of later invocations.  Moreover,
   739 locale operations (renaming and type / term instantiation) are applied
   740 to attribute arguments as expected.
   741 
   742 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
   743 actual attributes; rare situations may require Attrib.attribute to
   744 embed those attributes into Attrib.src that lack concrete syntax.
   745 Attribute implementations need to cooperate properly with the static
   746 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
   747 Attrib.XXX_thm etc. already do the right thing without further
   748 intervention.  Only unusual applications -- such as "where" or "of"
   749 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
   750 on the context and the facts involved -- may have to assign parsed
   751 values to argument tokens explicitly.
   752 
   753 * Changed parameter management in theorem generation for long goal
   754 statements with 'includes'.  INCOMPATIBILITY: produces a different
   755 theorem statement in rare situations.
   756 
   757 * Locale inspection command 'print_locale' omits notes elements.  Use
   758 'print_locale!' to have them included in the output.
   759 
   760 
   761 *** Provers ***
   762 
   763 * Provers/hypsubst.ML: improved version of the subst method, for
   764 single-step rewriting: it now works in bound variable contexts. New is
   765 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
   766 rewrite a different subterm than the original subst method, which is
   767 still available as 'simplesubst'.
   768 
   769 * Provers/quasi.ML: new transitivity reasoners for transitivity only
   770 and quasi orders.
   771 
   772 * Provers/trancl.ML: new transitivity reasoner for transitive and
   773 reflexive-transitive closure of relations.
   774 
   775 * Provers/blast.ML: new reference depth_limit to make blast's depth
   776 limit (previously hard-coded with a value of 20) user-definable.
   777 
   778 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
   779 is peformed already.  Object-logics merely need to finish their
   780 initial simpset configuration as before.  INCOMPATIBILITY.
   781 
   782 
   783 *** HOL ***
   784 
   785 * Symbolic syntax of Hilbert Choice Operator is now as follows:
   786 
   787   syntax (epsilon)
   788     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
   789 
   790 The symbol \<some> is displayed as the alternative epsilon of LaTeX
   791 and x-symbol; use option '-m epsilon' to get it actually printed.
   792 Moreover, the mathematically important symbolic identifier \<epsilon>
   793 becomes available as variable, constant etc.  INCOMPATIBILITY,
   794 
   795 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
   796 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
   797 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
   798 support corresponding Isar calculations.
   799 
   800 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
   801 instead of ":".
   802 
   803 * theory SetInterval: changed the syntax for open intervals:
   804 
   805   Old       New
   806   {..n(}    {..<n}
   807   {)n..}    {n<..}
   808   {m..n(}   {m..<n}
   809   {)m..n}   {m<..n}
   810   {)m..n(}  {m<..<n}
   811 
   812 The old syntax is still supported but will disappear in the next
   813 release.  For conversion use the following Emacs search and replace
   814 patterns (these are not perfect but work quite well):
   815 
   816   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
   817   \.\.\([^(}]*\)(}  ->  \.\.<\1}
   818 
   819 * Theory Commutative_Ring (in Library): method comm_ring for proving
   820 equalities in commutative rings; method 'algebra' provides a generic
   821 interface.
   822 
   823 * Theory Finite_Set: changed the syntax for 'setsum', summation over
   824 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
   825 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
   826 be a tuple pattern.
   827 
   828 Some new syntax forms are available:
   829 
   830   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
   831   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
   832   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
   833   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
   834 
   835 The latter form "\<Sum>x < k. e" used to be based on a separate
   836 function "Summation", which has been discontinued.
   837 
   838 * theory Finite_Set: in structured induction proofs, the insert case
   839 is now 'case (insert x F)' instead of the old counterintuitive 'case
   840 (insert F x)'.
   841 
   842 * The 'refute' command has been extended to support a much larger
   843 fragment of HOL, including axiomatic type classes, constdefs and
   844 typedefs, inductive datatypes and recursion.
   845 
   846 * New tactics 'sat' and 'satx' to prove propositional tautologies.
   847 Requires zChaff with proof generation to be installed.  See
   848 HOL/ex/SAT_Examples.thy for examples.
   849 
   850 * Datatype induction via method 'induct' now preserves the name of the
   851 induction variable. For example, when proving P(xs::'a list) by
   852 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
   853 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
   854 in unstructured proof scripts.
   855 
   856 * Reworked implementation of records.  Improved scalability for
   857 records with many fields, avoiding performance problems for type
   858 inference. Records are no longer composed of nested field types, but
   859 of nested extension types. Therefore the record type only grows linear
   860 in the number of extensions and not in the number of fields.  The
   861 top-level (users) view on records is preserved.  Potential
   862 INCOMPATIBILITY only in strange cases, where the theory depends on the
   863 old record representation. The type generated for a record is called
   864 <record_name>_ext_type.
   865 
   866 Flag record_quick_and_dirty_sensitive can be enabled to skip the
   867 proofs triggered by a record definition or a simproc (if
   868 quick_and_dirty is enabled).  Definitions of large records can take
   869 quite long.
   870 
   871 New simproc record_upd_simproc for simplification of multiple record
   872 updates enabled by default.  Moreover, trivial updates are also
   873 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
   874 occasionally, since simplification is more powerful by default.
   875 
   876 * typedef: proper support for polymorphic sets, which contain extra
   877 type-variables in the term.
   878 
   879 * Simplifier: automatically reasons about transitivity chains
   880 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
   881 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
   882 old proofs break occasionally as simplification may now solve more
   883 goals than previously.
   884 
   885 * Simplifier: converts x <= y into x = y if assumption y <= x is
   886 present.  Works for all partial orders (class "order"), in particular
   887 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
   888 just like y <= x.
   889 
   890 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
   891 bound variable or a constant then the let is unfolded.  Otherwise
   892 first a is simplified to b, and then f b is simplified to g. If
   893 possible we abstract b from g arriving at "let x = b in h x",
   894 otherwise we unfold the let and arrive at g.  The simproc can be
   895 enabled/disabled by the reference use_let_simproc.  Potential
   896 INCOMPATIBILITY since simplification is more powerful by default.
   897 
   898 * Classical reasoning: the meson method now accepts theorems as arguments.
   899 
   900 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
   901 jobs to provide advice on the provability of subgoals.
   902 
   903 * Theory OrderedGroup and Ring_and_Field: various additions and
   904 improvements to faciliate calculations involving equalities and
   905 inequalities.
   906 
   907 The following theorems have been eliminated or modified
   908 (INCOMPATIBILITY):
   909 
   910   abs_eq             now named abs_of_nonneg
   911   abs_of_ge_0        now named abs_of_nonneg
   912   abs_minus_eq       now named abs_of_nonpos
   913   imp_abs_id         now named abs_of_nonneg
   914   imp_abs_neg_id     now named abs_of_nonpos
   915   mult_pos           now named mult_pos_pos
   916   mult_pos_le        now named mult_nonneg_nonneg
   917   mult_pos_neg_le    now named mult_nonneg_nonpos
   918   mult_pos_neg2_le   now named mult_nonneg_nonpos2
   919   mult_neg           now named mult_neg_neg
   920   mult_neg_le        now named mult_nonpos_nonpos
   921 
   922 * Theory Parity: added rules for simplifying exponents.
   923 
   924 * Theory List:
   925 
   926 The following theorems have been eliminated or modified
   927 (INCOMPATIBILITY):
   928 
   929   list_all_Nil       now named list_all.simps(1)
   930   list_all_Cons      now named list_all.simps(2)
   931   list_all_conv      now named list_all_iff
   932   set_mem_eq         now named mem_iff
   933 
   934 * Theories SetsAndFunctions and BigO (see HOL/Library) support
   935 asymptotic "big O" calculations.  See the notes in BigO.thy.
   936 
   937 
   938 *** HOL-Complex ***
   939 
   940 * Theory RealDef: better support for embedding natural numbers and
   941 integers in the reals.
   942 
   943 The following theorems have been eliminated or modified
   944 (INCOMPATIBILITY):
   945 
   946   exp_ge_add_one_self  now requires no hypotheses
   947   real_of_int_add      reversed direction of equality (use [symmetric])
   948   real_of_int_minus    reversed direction of equality (use [symmetric])
   949   real_of_int_diff     reversed direction of equality (use [symmetric])
   950   real_of_int_mult     reversed direction of equality (use [symmetric])
   951 
   952 * Theory RComplete: expanded support for floor and ceiling functions.
   953 
   954 * Theory Ln is new, with properties of the natural logarithm
   955 
   956 * Hyperreal: There is a new type constructor "star" for making
   957 nonstandard types.  The old type names are now type synonyms:
   958 
   959   hypreal = real star
   960   hypnat = nat star
   961   hcomplex = complex star
   962 
   963 * Hyperreal: Many groups of similarly-defined constants have been
   964 replaced by polymorphic versions (INCOMPATIBILITY):
   965 
   966   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
   967 
   968   starset      <-- starsetNat, starsetC
   969   *s*          <-- *sNat*, *sc*
   970   starset_n    <-- starsetNat_n, starsetC_n
   971   *sn*         <-- *sNatn*, *scn*
   972   InternalSets <-- InternalNatSets, InternalCSets
   973 
   974   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
   975   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
   976   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
   977   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
   978   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
   979 
   980 * Hyperreal: Many type-specific theorems have been removed in favor of
   981 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
   982 
   983   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
   984   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
   985   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
   986   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
   987   right_minus <-- hypreal_add_minus
   988   left_minus <-- {hypreal,hcomplex}_add_minus_left
   989   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
   990   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
   991   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
   992   mult_1_right <-- hcomplex_mult_one_right
   993   mult_zero_left <-- hcomplex_mult_zero_left
   994   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
   995   right_distrib <-- hypnat_add_mult_distrib2
   996   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
   997   right_inverse <-- hypreal_mult_inverse
   998   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
   999   order_refl <-- {hypreal,hypnat}_le_refl
  1000   order_trans <-- {hypreal,hypnat}_le_trans
  1001   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1002   order_less_le <-- {hypreal,hypnat}_less_le
  1003   linorder_linear <-- {hypreal,hypnat}_le_linear
  1004   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1005   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1006   add_nonneg_nonneg <-- hypreal_le_add_order
  1007 
  1008 * Hyperreal: Separate theorems having to do with type-specific
  1009 versions of constants have been merged into theorems that apply to the
  1010 new polymorphic constants (INCOMPATIBILITY):
  1011 
  1012   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1013   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1014   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1015   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1016   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1017   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1018   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1019   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1020   STAR_diff <-- {STAR,STARC}_diff
  1021   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1022     STARC_hcomplex_of_complex}_image_subset
  1023   starset_n_Un <-- starset{Nat,C}_n_Un
  1024   starset_n_Int <-- starset{Nat,C}_n_Int
  1025   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1026   starset_n_diff <-- starset{Nat,C}_n_diff
  1027   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1028   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1029   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1030   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1031   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1032   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1033   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1034   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1035   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1036   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1037   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1038   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1039   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1040   starfun_diff <-- starfun{C,RC,CR}_diff
  1041   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1042   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1043   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1044   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1045   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1046   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1047   starfun_Id <-- starfunC_Id
  1048   starfun_approx <-- starfun{Nat,CR}_approx
  1049   starfun_capprox <-- starfun{C,RC}_capprox
  1050   starfun_abs <-- starfunNat_rabs
  1051   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  1052   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  1053   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  1054   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  1055   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  1056   starfun_add_approx <-- starfunCR_add_approx
  1057   starfun_inverse_inverse <-- starfunC_inverse_inverse
  1058   starfun_divide <-- starfun{C,CR,RC}_divide
  1059   starfun_n <-- starfun{Nat,C}_n
  1060   starfun_n_mult <-- starfun{Nat,C}_n_mult
  1061   starfun_n_add <-- starfun{Nat,C}_n_add
  1062   starfun_n_add_minus <-- starfunNat_n_add_minus
  1063   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  1064   starfun_n_minus <-- starfun{Nat,C}_n_minus
  1065   starfun_n_eq <-- starfun{Nat,C}_n_eq
  1066 
  1067   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  1068   star_n_minus <-- {hypreal,hcomplex}_minus
  1069   star_n_diff <-- {hypreal,hcomplex}_diff
  1070   star_n_mult <-- {hypreal,hcomplex}_mult
  1071   star_n_inverse <-- {hypreal,hcomplex}_inverse
  1072   star_n_le <-- {hypreal,hypnat}_le
  1073   star_n_less <-- {hypreal,hypnat}_less
  1074   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  1075   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  1076   star_n_abs <-- hypreal_hrabs
  1077   star_n_divide <-- hcomplex_divide
  1078 
  1079   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  1080   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  1081   star_of_diff <-- hypreal_of_real_diff
  1082   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  1083   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  1084   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  1085   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  1086   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  1087   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  1088   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  1089   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  1090   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  1091   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  1092   star_of_number_of <-- {hypreal,hcomplex}_number_of
  1093   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  1094   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  1095   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  1096   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  1097   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  1098   star_of_power <-- hypreal_of_real_power
  1099   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  1100 
  1101 * Hyperreal: new method "transfer" that implements the transfer
  1102 principle of nonstandard analysis. With a subgoal that mentions
  1103 nonstandard types like "'a star", the command "apply transfer"
  1104 replaces it with an equivalent one that mentions only standard types.
  1105 To be successful, all free variables must have standard types; non-
  1106 standard variables must have explicit universal quantifiers.
  1107 
  1108 * Hyperreal: A theory of Taylor series.
  1109 
  1110 
  1111 *** HOLCF ***
  1112 
  1113 * Discontinued special version of 'constdefs' (which used to support
  1114 continuous functions) in favor of the general Pure one with full
  1115 type-inference.
  1116 
  1117 * New simplification procedure for solving continuity conditions; it
  1118 is much faster on terms with many nested lambda abstractions (cubic
  1119 instead of exponential time).
  1120 
  1121 * New syntax for domain package: selector names are now optional.
  1122 Parentheses should be omitted unless argument is lazy, for example:
  1123 
  1124   domain 'a stream = cons "'a" (lazy "'a stream")
  1125 
  1126 * New command 'fixrec' for defining recursive functions with pattern
  1127 matching; defining multiple functions with mutual recursion is also
  1128 supported.  Patterns may include the constants cpair, spair, up, sinl,
  1129 sinr, or any data constructor defined by the domain package. The given
  1130 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  1131 syntax and examples.
  1132 
  1133 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  1134 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  1135 but the proof obligation additionally includes an admissibility
  1136 requirement. The packages generate instances of class cpo or pcpo,
  1137 with continuity and strictness theorems for Rep and Abs.
  1138 
  1139 * HOLCF: Many theorems have been renamed according to a more standard naming
  1140 scheme (INCOMPATIBILITY):
  1141 
  1142   foo_inject:  "foo$x = foo$y ==> x = y"
  1143   foo_eq:      "(foo$x = foo$y) = (x = y)"
  1144   foo_less:    "(foo$x << foo$y) = (x << y)"
  1145   foo_strict:  "foo$UU = UU"
  1146   foo_defined: "... ==> foo$x ~= UU"
  1147   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  1148 
  1149 
  1150 *** ZF ***
  1151 
  1152 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  1153 including the First Isomorphism Theorem (on quotienting by the kernel
  1154 of a homomorphism).
  1155 
  1156 * ZF/Simplifier: install second copy of type solver that actually
  1157 makes use of TC rules declared to Isar proof contexts (or locales);
  1158 the old version is still required for ML proof scripts.
  1159 
  1160 
  1161 *** Cube ***
  1162 
  1163 * Converted to Isar theory format; use locales instead of axiomatic
  1164 theories.
  1165 
  1166 
  1167 *** ML ***
  1168 
  1169 * Pure/library.ML no longer defines its own option datatype, but uses
  1170 that of the SML basis, which has constructors NONE and SOME instead of
  1171 None and Some, as well as exception Option.Option instead of OPTION.
  1172 The functions the, if_none, is_some, is_none have been adapted
  1173 accordingly, while Option.map replaces apsome.
  1174 
  1175 * Pure/library.ML: the exception LIST has been given up in favour of
  1176 the standard exceptions Empty and Subscript, as well as
  1177 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  1178 superceded by the standard hd and tl functions etc.
  1179 
  1180 A number of basic list functions are no longer exported to the ML
  1181 toplevel, as they are variants of predefined functions.  The following
  1182 suggests how one can translate existing code:
  1183 
  1184     rev_append xs ys = List.revAppend (xs, ys)
  1185     nth_elem (i, xs) = List.nth (xs, i)
  1186     last_elem xs = List.last xs
  1187     flat xss = List.concat xss
  1188     seq fs = List.app fs
  1189     partition P xs = List.partition P xs
  1190     mapfilter f xs = List.mapPartial f xs
  1191 
  1192 * Pure/library.ML: several combinators for linear functional
  1193 transformations, notably reverse application and composition:
  1194 
  1195   x |> f                f #> g
  1196   (x, y) |-> f          f #-> g
  1197 
  1198 * Pure/library.ML: introduced/changed precedence of infix operators:
  1199 
  1200   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  1201   infix 2 ?;
  1202   infix 3 o oo ooo oooo;
  1203   infix 4 ~~ upto downto;
  1204 
  1205 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  1206 infix operators.
  1207 
  1208 * Pure/library.ML: natural list combinators fold, fold_rev, and
  1209 fold_map support linear functional transformations and nesting.  For
  1210 example:
  1211 
  1212   fold f [x1, ..., xN] y =
  1213     y |> f x1 |> ... |> f xN
  1214 
  1215   (fold o fold) f [xs1, ..., xsN] y =
  1216     y |> fold f xs1 |> ... |> fold f xsN
  1217 
  1218   fold f [x1, ..., xN] =
  1219     f x1 #> ... #> f xN
  1220 
  1221   (fold o fold) f [xs1, ..., xsN] =
  1222     fold f xs1 #> ... #> fold f xsN
  1223 
  1224 * Pure/library.ML: the following selectors on type 'a option are
  1225 available:
  1226 
  1227   the:               'a option -> 'a  (*partial*)
  1228   these:             'a option -> 'a  where 'a = 'b list
  1229   the_default: 'a -> 'a option -> 'a
  1230   the_list:          'a option -> 'a list
  1231 
  1232 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1233 basic operations for association lists, following natural argument
  1234 order; moreover the explicit equality predicate passed here avoids
  1235 potentially expensive polymorphic runtime equality checks.
  1236 The old functions may be expressed as follows:
  1237 
  1238   assoc = uncurry (AList.lookup (op =))
  1239   assocs = these oo AList.lookup (op =)
  1240   overwrite = uncurry (AList.update (op =)) o swap
  1241 
  1242 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  1243 
  1244   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  1245   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  1246 
  1247 replacing make_keylist and keyfilter (occassionally used)
  1248 Naive rewrites:
  1249 
  1250   make_keylist = AList.make
  1251   keyfilter = AList.find (op =)
  1252 
  1253 * eq_fst and eq_snd now take explicit equality parameter, thus
  1254   avoiding eqtypes. Naive rewrites:
  1255 
  1256     eq_fst = eq_fst (op =)
  1257     eq_snd = eq_snd (op =)
  1258 
  1259 * Removed deprecated apl and apr (rarely used).
  1260   Naive rewrites:
  1261 
  1262     apl (n, op) =>>= curry op n
  1263     apr (op, m) =>>= fn n => op (n, m)
  1264 
  1265 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  1266 provides a reasonably efficient light-weight implementation of sets as
  1267 lists.
  1268 
  1269 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  1270 few new operations; existing lookup and update are now curried to
  1271 follow natural argument order (for use with fold etc.);
  1272 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  1273 
  1274 * Pure/General: output via the Isabelle channels of
  1275 writeln/warning/error etc. is now passed through Output.output, with a
  1276 hook for arbitrary transformations depending on the print_mode
  1277 (cf. Output.add_mode -- the first active mode that provides a output
  1278 function wins).  Already formatted output may be embedded into further
  1279 text via Output.raw; the result of Pretty.string_of/str_of and derived
  1280 functions (string_of_term/cterm/thm etc.) is already marked raw to
  1281 accommodate easy composition of diagnostic messages etc.  Programmers
  1282 rarely need to care about Output.output or Output.raw at all, with
  1283 some notable exceptions: Output.output is required when bypassing the
  1284 standard channels (writeln etc.), or in token translations to produce
  1285 properly formatted results; Output.raw is required when capturing
  1286 already output material that will eventually be presented to the user
  1287 a second time.  For the default print mode, both Output.output and
  1288 Output.raw have no effect.
  1289 
  1290 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  1291 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  1292 cumulative results are displayed at the end of a batch session.
  1293 
  1294 * Pure/General: File.sysify_path and File.quote_sysify path have been
  1295 replaced by File.platform_path and File.shell_path (with appropriate
  1296 hooks).  This provides a clean interface for unusual systems where the
  1297 internal and external process view of file names are different.
  1298 
  1299 * Pure: more efficient orders for basic syntactic entities: added
  1300 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  1301 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  1302 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  1303 orders now -- potential INCOMPATIBILITY for code that depends on a
  1304 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  1305 Library.sort_strings on result).
  1306 
  1307 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  1308 fold_types traverse types/terms from left to right, observing natural
  1309 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  1310 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  1311 
  1312 * Pure: name spaces have been refined, with significant changes of the
  1313 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  1314 to extern(_table).  The plain name entry path is superceded by a
  1315 general 'naming' context, which also includes the 'policy' to produce
  1316 a fully qualified name and external accesses of a fully qualified
  1317 name; NameSpace.extend is superceded by context dependent
  1318 Sign.declare_name.  Several theory and proof context operations modify
  1319 the naming context.  Especially note Theory.restore_naming and
  1320 ProofContext.restore_naming to get back to a sane state; note that
  1321 Theory.add_path is no longer sufficient to recover from
  1322 Theory.absolute_path in particular.
  1323 
  1324 * Pure: new flags short_names (default false) and unique_names
  1325 (default true) for controlling output of qualified names.  If
  1326 short_names is set, names are printed unqualified.  If unique_names is
  1327 reset, the name prefix is reduced to the minimum required to achieve
  1328 the original result when interning again, even if there is an overlap
  1329 with earlier declarations.
  1330 
  1331 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  1332 now 'extend', and 'merge' gets an additional Pretty.pp argument
  1333 (useful for printing error messages).  INCOMPATIBILITY.
  1334 
  1335 * Pure: major reorganization of the theory context.  Type Sign.sg and
  1336 Theory.theory are now identified, referring to the universal
  1337 Context.theory (see Pure/context.ML).  Actual signature and theory
  1338 content is managed as theory data.  The old code and interfaces were
  1339 spread over many files and structures; the new arrangement introduces
  1340 considerable INCOMPATIBILITY to gain more clarity:
  1341 
  1342   Context -- theory management operations (name, identity, inclusion,
  1343     parents, ancestors, merge, etc.), plus generic theory data;
  1344 
  1345   Sign -- logical signature and syntax operations (declaring consts,
  1346     types, etc.), plus certify/read for common entities;
  1347 
  1348   Theory -- logical theory operations (stating axioms, definitions,
  1349     oracles), plus a copy of logical signature operations (consts,
  1350     types, etc.); also a few basic management operations (Theory.copy,
  1351     Theory.merge, etc.)
  1352 
  1353 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  1354 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  1355 for convenience -- they merely return the theory.
  1356 
  1357 * Pure: type Type.tsig is superceded by theory in most interfaces.
  1358 
  1359 * Pure: the Isar proof context type is already defined early in Pure
  1360 as Context.proof (note that ProofContext.context and Proof.context are
  1361 aliases, where the latter is the preferred name).  This enables other
  1362 Isabelle components to refer to that type even before Isar is present.
  1363 
  1364 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  1365 typeK, constK, axiomK, oracleK), but provide explicit operations for
  1366 any of these kinds.  For example, Sign.intern typeK is now
  1367 Sign.intern_type, Theory.hide_space Sign.typeK is now
  1368 Theory.hide_types.  Also note that former
  1369 Theory.hide_classes/types/consts are now
  1370 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  1371 internalize their arguments!  INCOMPATIBILITY.
  1372 
  1373 * Pure: get_thm interface (of PureThy and ProofContext) expects
  1374 datatype thmref (with constructors Name and NameSelection) instead of
  1375 plain string -- INCOMPATIBILITY;
  1376 
  1377 * Pure: cases produced by proof methods specify options, where NONE
  1378 means to remove case bindings -- INCOMPATIBILITY in
  1379 (RAW_)METHOD_CASES.
  1380 
  1381 * Pure: the following operations retrieve axioms or theorems from a
  1382 theory node or theory hierarchy, respectively:
  1383 
  1384   Theory.axioms_of: theory -> (string * term) list
  1385   Theory.all_axioms_of: theory -> (string * term) list
  1386   PureThy.thms_of: theory -> (string * thm) list
  1387   PureThy.all_thms_of: theory -> (string * thm) list
  1388 
  1389 * Pure: print_tac now outputs the goal through the trace channel.
  1390 
  1391 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  1392 Reference Toplevel.debug (default false) controls detailed printing
  1393 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  1394 controls execution profiling -- set to 1 for time and 2 for space
  1395 (both increase the runtime).
  1396 
  1397 * Isar session: The initial use of ROOT.ML is now always timed,
  1398 i.e. the log will show the actual process times, in contrast to the
  1399 elapsed wall-clock time that the outer shell wrapper produces.
  1400 
  1401 * Simplifier: improved handling of bound variables (nameless
  1402 representation, avoid allocating new strings).  Simprocs that invoke
  1403 the Simplifier recursively should use Simplifier.inherit_bounds to
  1404 avoid local name clashes.  Failure to do so produces warnings
  1405 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  1406 for further details.
  1407 
  1408 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  1409 bindings for all theorems stored within a given theory; this may help
  1410 in porting non-Isar theories to Isar ones, while keeping ML proof
  1411 scripts for the time being.
  1412 
  1413 * ML operator HTML.with_charset specifies the charset begin used for
  1414 generated HTML files.  For example:
  1415 
  1416   HTML.with_charset "utf-8" use_thy "Hebrew";
  1417   HTML.with_charset "utf-8" use_thy "Chinese";
  1418 
  1419 
  1420 *** System ***
  1421 
  1422 * Allow symlinks to all proper Isabelle executables (Isabelle,
  1423 isabelle, isatool etc.).
  1424 
  1425 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  1426 isatool doc, isatool mkdir, display_drafts etc.).
  1427 
  1428 * isatool usedir: option -f allows specification of the ML file to be
  1429 used by Isabelle; default is ROOT.ML.
  1430 
  1431 * New isatool version outputs the version identifier of the Isabelle
  1432 distribution being used.
  1433 
  1434 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  1435 (containing Boolean satisfiability problems) into Isabelle/HOL
  1436 theories.
  1437 
  1438 
  1439 
  1440 New in Isabelle2004 (April 2004)
  1441 --------------------------------
  1442 
  1443 *** General ***
  1444 
  1445 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  1446   Replaces linorder.ML.
  1447 
  1448 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  1449   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  1450   (\<a>...\<z>), are now considered normal letters, and can therefore
  1451   be used anywhere where an ASCII letter (a...zA...Z) has until
  1452   now. COMPATIBILITY: This obviously changes the parsing of some
  1453   terms, especially where a symbol has been used as a binder, say
  1454   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  1455   as an identifier.  Fix it by inserting a space around former
  1456   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  1457   existing theory and ML files.
  1458 
  1459 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  1460 
  1461 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  1462   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  1463   a normal (but invisible) letter. For multiple letter subscripts repeat
  1464   \<^isub> like this: x\<^isub>1\<^isub>2.
  1465 
  1466 * Pure: There are now sub-/superscripts that can span more than one
  1467   character. Text between \<^bsub> and \<^esub> is set in subscript in
  1468   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  1469   superscript. The new control characters are not identifier parts.
  1470 
  1471 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  1472   content of "..." to the latex file instead of \isacntrl... . The "..."
  1473   may consist of any printable characters excluding the end bracket >.
  1474 
  1475 * Pure: Using new Isar command "finalconsts" (or the ML functions
  1476   Theory.add_finals or Theory.add_finals_i) it is now possible to
  1477   declare constants "final", which prevents their being given a definition
  1478   later.  It is useful for constants whose behaviour is fixed axiomatically
  1479   rather than definitionally, such as the meta-logic connectives.
  1480 
  1481 * Pure: 'instance' now handles general arities with general sorts
  1482   (i.e. intersections of classes),
  1483 
  1484 * Presentation: generated HTML now uses a CSS style sheet to make layout
  1485   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  1486   It can be changed to alter the colors/layout of generated pages.
  1487 
  1488 
  1489 *** Isar ***
  1490 
  1491 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  1492   cut_tac, subgoal_tac and thin_tac:
  1493   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  1494     locales are no longer forced to write Isar proof scripts.
  1495     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  1496     emulations.
  1497   - INCOMPATIBILITY: names of variables to be instantiated may no
  1498     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  1499     This is consistent with the instantiation attribute "where".
  1500 
  1501 * Attributes "where" and "of":
  1502   - Now take type variables of instantiated theorem into account when reading
  1503     the instantiation string.  This fixes a bug that caused instantiated
  1504     theorems to have too special types in some circumstances.
  1505   - "where" permits explicit instantiations of type variables.
  1506 
  1507 * Calculation commands "moreover" and "also" no longer interfere with
  1508   current facts ("this"), admitting arbitrary combinations with "then"
  1509   and derived forms.
  1510 
  1511 * Locales:
  1512   - Goal statements involving the context element "includes" no longer
  1513     generate theorems with internal delta predicates (those ending on
  1514     "_axioms") in the premise.
  1515     Resolve particular premise with <locale>.intro to obtain old form.
  1516   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  1517     specification and "includes" elements in goal statement.
  1518   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  1519     [intro?] and [elim?] (respectively) by default.
  1520   - Experimental command for instantiation of locales in proof contexts:
  1521         instantiate <label>[<attrs>]: <loc>
  1522     Instantiates locale <loc> and adds all its theorems to the current context
  1523     taking into account their attributes.  Label and attrs are optional
  1524     modifiers, like in theorem declarations.  If present, names of
  1525     instantiated theorems are qualified with <label>, and the attributes
  1526     <attrs> are applied after any attributes these theorems might have already.
  1527       If the locale has assumptions, a chained fact of the form
  1528     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  1529     are derived.  The command does not support old-style locales declared
  1530     with "locale (open)".
  1531       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  1532 
  1533 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  1534   (Isar) contexts.
  1535 
  1536 
  1537 *** HOL ***
  1538 
  1539 * Proof import: new image HOL4 contains the imported library from
  1540   the HOL4 system with about 2500 theorems. It is imported by
  1541   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  1542   can be used like any other Isabelle image.  See
  1543   HOL/Import/HOL/README for more information.
  1544 
  1545 * Simplifier:
  1546   - Much improved handling of linear and partial orders.
  1547     Reasoners for linear and partial orders are set up for type classes
  1548     "linorder" and "order" respectively, and are added to the default simpset
  1549     as solvers.  This means that the simplifier can build transitivity chains
  1550     to solve goals from the assumptions.
  1551   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  1552     of blast or auto after simplification become unnecessary because the goal
  1553     is solved by simplification already.
  1554 
  1555 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  1556     all proved in axiomatic type classes for semirings, rings and fields.
  1557 
  1558 * Numerics:
  1559   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  1560     now formalized using the Ring_and_Field theory mentioned above.
  1561   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  1562     than before, because now they are set up once in a generic manner.
  1563   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  1564     Look for the general versions in Ring_and_Field (and Power if they concern
  1565     exponentiation).
  1566 
  1567 * Type "rat" of the rational numbers is now available in HOL-Complex.
  1568 
  1569 * Records:
  1570   - Record types are now by default printed with their type abbreviation
  1571     instead of the list of all field types. This can be configured via
  1572     the reference "print_record_type_abbr".
  1573   - Simproc "record_upd_simproc" for simplification of multiple updates added
  1574     (not enabled by default).
  1575   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  1576     EX x. x = sel r to True (not enabled by default).
  1577   - Tactic "record_split_simp_tac" to split and simplify records added.
  1578 
  1579 * 'specification' command added, allowing for definition by
  1580   specification.  There is also an 'ax_specification' command that
  1581   introduces the new constants axiomatically.
  1582 
  1583 * arith(_tac) is now able to generate counterexamples for reals as well.
  1584 
  1585 * HOL-Algebra: new locale "ring" for non-commutative rings.
  1586 
  1587 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  1588   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  1589 
  1590 * HOL-Matrix: a first theory for matrices in HOL with an application of
  1591   matrix theory to linear programming.
  1592 
  1593 * Unions and Intersections:
  1594   The latex output syntax of UN and INT has been changed
  1595   from "\Union x \in A. B" to "\Union_{x \in A} B"
  1596   i.e. the index formulae has become a subscript.
  1597   Similarly for "\Union x. B", and for \Inter instead of \Union.
  1598 
  1599 * Unions and Intersections over Intervals:
  1600   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  1601   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  1602   like in normal math, and corresponding versions for < and for intersection.
  1603 
  1604 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  1605   lexicographic dictonary ordering has been added as "lexord".
  1606 
  1607 * ML: the legacy theory structures Int and List have been removed. They had
  1608   conflicted with ML Basis Library structures having the same names.
  1609 
  1610 * 'refute' command added to search for (finite) countermodels.  Only works
  1611   for a fragment of HOL.  The installation of an external SAT solver is
  1612   highly recommended.  See "HOL/Refute.thy" for details.
  1613 
  1614 * 'quickcheck' command: Allows to find counterexamples by evaluating
  1615   formulae under an assignment of free variables to random values.
  1616   In contrast to 'refute', it can deal with inductive datatypes,
  1617   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  1618   for examples.
  1619 
  1620 
  1621 *** HOLCF ***
  1622 
  1623 * Streams now come with concatenation and are part of the HOLCF image
  1624 
  1625 
  1626 
  1627 New in Isabelle2003 (May 2003)
  1628 ------------------------------
  1629 
  1630 *** General ***
  1631 
  1632 * Provers/simplifier:
  1633 
  1634   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  1635     Assumptions are now subject to complete mutual simplification,
  1636     not just from left to right. The simplifier now preserves
  1637     the order of assumptions.
  1638 
  1639     Potential INCOMPATIBILITY:
  1640 
  1641     -- simp sometimes diverges where the old version did
  1642        not, e.g. invoking simp on the goal
  1643 
  1644         [| P (f x); y = x; f x = f y |] ==> Q
  1645 
  1646        now gives rise to the infinite reduction sequence
  1647 
  1648         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  1649 
  1650        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  1651        kind of problem.
  1652 
  1653     -- Tactics combining classical reasoner and simplification (such as auto)
  1654        are also affected by this change, because many of them rely on
  1655        simp. They may sometimes diverge as well or yield a different numbers
  1656        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  1657        in case of problems. Sometimes subsequent calls to the classical
  1658        reasoner will fail because a preceeding call to the simplifier too
  1659        eagerly simplified the goal, e.g. deleted redundant premises.
  1660 
  1661   - The simplifier trace now shows the names of the applied rewrite rules
  1662 
  1663   - You can limit the number of recursive invocations of the simplifier
  1664     during conditional rewriting (where the simplifie tries to solve the
  1665     conditions before applying the rewrite rule):
  1666     ML "simp_depth_limit := n"
  1667     where n is an integer. Thus you can force termination where previously
  1668     the simplifier would diverge.
  1669 
  1670   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  1671 
  1672   - No longer aborts on failed congruence proof.  Instead, the
  1673     congruence is ignored.
  1674 
  1675 * Pure: New generic framework for extracting programs from constructive
  1676   proofs. See HOL/Extraction.thy for an example instantiation, as well
  1677   as HOL/Extraction for some case studies.
  1678 
  1679 * Pure: The main goal of the proof state is no longer shown by default, only
  1680 the subgoals. This behaviour is controlled by a new flag.
  1681    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  1682 (ML: Proof.show_main_goal).
  1683 
  1684 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  1685 rules whose conclusion matches subgoal 1:
  1686       PG menu: Isabelle/Isar -> Show me -> matching rules
  1687 The rules are ordered by how closely they match the subgoal.
  1688 In particular, rules that solve a subgoal outright are displayed first
  1689 (or rather last, the way they are printed).
  1690 (ML: ProofGeneral.print_intros())
  1691 
  1692 * Pure: New flag trace_unify_fail causes unification to print
  1693 diagnostic information (PG: in trace buffer) when it fails. This is
  1694 useful for figuring out why single step proofs like rule, erule or
  1695 assumption failed.
  1696 
  1697 * Pure: Locale specifications now produce predicate definitions
  1698 according to the body of text (covering assumptions modulo local
  1699 definitions); predicate "loc_axioms" covers newly introduced text,
  1700 while "loc" is cumulative wrt. all included locale expressions; the
  1701 latter view is presented only on export into the global theory
  1702 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  1703 on the old view without predicates;
  1704 
  1705 * Pure: predefined locales "var" and "struct" are useful for sharing
  1706 parameters (as in CASL, for example); just specify something like
  1707 ``var x + var y + struct M'' as import;
  1708 
  1709 * Pure: improved thms_containing: proper indexing of facts instead of
  1710 raw theorems; check validity of results wrt. current name space;
  1711 include local facts of proof configuration (also covers active
  1712 locales), cover fixed variables in index; may use "_" in term
  1713 specification; an optional limit for the number of printed facts may
  1714 be given (the default is 40);
  1715 
  1716 * Pure: disallow duplicate fact bindings within new-style theory files
  1717 (batch-mode only);
  1718 
  1719 * Provers: improved induct method: assumptions introduced by case
  1720 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  1721 the goal statement); "foo" still refers to all facts collectively;
  1722 
  1723 * Provers: the function blast.overloaded has been removed: all constants
  1724 are regarded as potentially overloaded, which improves robustness in exchange
  1725 for slight decrease in efficiency;
  1726 
  1727 * Provers/linorder: New generic prover for transitivity reasoning over
  1728 linear orders.  Note: this prover is not efficient!
  1729 
  1730 * Isar: preview of problems to finish 'show' now produce an error
  1731 rather than just a warning (in interactive mode);
  1732 
  1733 
  1734 *** HOL ***
  1735 
  1736 * arith(_tac)
  1737 
  1738  - Produces a counter example if it cannot prove a goal.
  1739    Note that the counter example may be spurious if the goal is not a formula
  1740    of quantifier-free linear arithmetic.
  1741    In ProofGeneral the counter example appears in the trace buffer.
  1742 
  1743  - Knows about div k and mod k where k is a numeral of type nat or int.
  1744 
  1745  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  1746    linear arithmetic fails. This takes account of quantifiers and divisibility.
  1747    Presburger arithmetic can also be called explicitly via presburger(_tac).
  1748 
  1749 * simp's arithmetic capabilities have been enhanced a bit: it now
  1750 takes ~= in premises into account (by performing a case split);
  1751 
  1752 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  1753 are distributed over a sum of terms;
  1754 
  1755 * New tactic "trans_tac" and method "trans" instantiate
  1756 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  1757 "<=", "<" and "=").
  1758 
  1759 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  1760 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  1761 
  1762 * 'typedef' command has new option "open" to suppress the set
  1763 definition;
  1764 
  1765 * functions Min and Max on finite sets have been introduced (theory
  1766 Finite_Set);
  1767 
  1768 * attribute [symmetric] now works for relations as well; it turns
  1769 (x,y) : R^-1 into (y,x) : R, and vice versa;
  1770 
  1771 * induct over a !!-quantified statement (say !!x1..xn):
  1772   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  1773 
  1774 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  1775 %x. None. Warning: empty_def now refers to the previously hidden definition
  1776 of the empty set.
  1777 
  1778 * Algebra: formalization of classical algebra.  Intended as base for
  1779 any algebraic development in Isabelle.  Currently covers group theory
  1780 (up to Sylow's theorem) and ring theory (Universal Property of
  1781 Univariate Polynomials).  Contributions welcome;
  1782 
  1783 * GroupTheory: deleted, since its material has been moved to Algebra;
  1784 
  1785 * Complex: new directory of the complex numbers with numeric constants,
  1786 nonstandard complex numbers, and some complex analysis, standard and
  1787 nonstandard (Jacques Fleuriot);
  1788 
  1789 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  1790 
  1791 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  1792 Fleuriot);
  1793 
  1794 * Real/HahnBanach: updated and adapted to locales;
  1795 
  1796 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  1797 Gray and Kramer);
  1798 
  1799 * UNITY: added the Meier-Sanders theory of progress sets;
  1800 
  1801 * MicroJava: bytecode verifier and lightweight bytecode verifier
  1802 as abstract algorithms, instantiated to the JVM;
  1803 
  1804 * Bali: Java source language formalization. Type system, operational
  1805 semantics, axiomatic semantics. Supported language features:
  1806 classes, interfaces, objects,virtual methods, static methods,
  1807 static/instance fields, arrays, access modifiers, definite
  1808 assignment, exceptions.
  1809 
  1810 
  1811 *** ZF ***
  1812 
  1813 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  1814 universe, etc.);
  1815 
  1816 * Main ZF: virtually all theories converted to new-style format;
  1817 
  1818 
  1819 *** ML ***
  1820 
  1821 * Pure: Tactic.prove provides sane interface for internal proofs;
  1822 omits the infamous "standard" operation, so this is more appropriate
  1823 than prove_goalw_cterm in many situations (e.g. in simprocs);
  1824 
  1825 * Pure: improved error reporting of simprocs;
  1826 
  1827 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  1828 up simprocs;
  1829 
  1830 
  1831 *** Document preparation ***
  1832 
  1833 * uses \par instead of \\ for line breaks in theory text. This may
  1834 shift some page breaks in large documents. To get the old behaviour
  1835 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  1836 
  1837 * minimized dependencies of isabelle.sty and isabellesym.sty on
  1838 other packages
  1839 
  1840 * \<euro> now needs package babel/greek instead of marvosym (which
  1841 broke \Rightarrow)
  1842 
  1843 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  1844 textcomp package)
  1845 
  1846 
  1847 
  1848 New in Isabelle2002 (March 2002)
  1849 --------------------------------
  1850 
  1851 *** Document preparation ***
  1852 
  1853 * greatly simplified document preparation setup, including more
  1854 graceful interpretation of isatool usedir -i/-d/-D options, and more
  1855 instructive isatool mkdir; users should basically be able to get
  1856 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  1857 users may run a separate document processing stage manually like this:
  1858 "isatool usedir -D output HOL Test && isatool document Test/output";
  1859 
  1860 * theory dependency graph may now be incorporated into documents;
  1861 isatool usedir -g true will produce session_graph.eps/.pdf for use
  1862 with \includegraphics of LaTeX;
  1863 
  1864 * proper spacing of consecutive markup elements, especially text
  1865 blocks after section headings;
  1866 
  1867 * support bold style (for single symbols only), input syntax is like
  1868 this: "\<^bold>\<alpha>" or "\<^bold>A";
  1869 
  1870 * \<bullet> is now output as bold \cdot by default, which looks much
  1871 better in printed text;
  1872 
  1873 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  1874 note that these symbols are currently unavailable in Proof General /
  1875 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  1876 
  1877 * isatool latex no longer depends on changed TEXINPUTS, instead
  1878 isatool document copies the Isabelle style files to the target
  1879 location;
  1880 
  1881 
  1882 *** Isar ***
  1883 
  1884 * Pure/Provers: improved proof by cases and induction;
  1885   - 'case' command admits impromptu naming of parameters (such as
  1886     "case (Suc n)");
  1887   - 'induct' method divinates rule instantiation from the inductive
  1888     claim; no longer requires excessive ?P bindings for proper
  1889     instantiation of cases;
  1890   - 'induct' method properly enumerates all possibilities of set/type
  1891     rules; as a consequence facts may be also passed through *type*
  1892     rules without further ado;
  1893   - 'induct' method now derives symbolic cases from the *rulified*
  1894     rule (before it used to rulify cases stemming from the internal
  1895     atomized version); this means that the context of a non-atomic
  1896     statement becomes is included in the hypothesis, avoiding the
  1897     slightly cumbersome show "PROP ?case" form;
  1898   - 'induct' may now use elim-style induction rules without chaining
  1899     facts, using ``missing'' premises from the goal state; this allows
  1900     rules stemming from inductive sets to be applied in unstructured
  1901     scripts, while still benefitting from proper handling of non-atomic
  1902     statements; NB: major inductive premises need to be put first, all
  1903     the rest of the goal is passed through the induction;
  1904   - 'induct' proper support for mutual induction involving non-atomic
  1905     rule statements (uses the new concept of simultaneous goals, see
  1906     below);
  1907   - append all possible rule selections, but only use the first
  1908     success (no backtracking);
  1909   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  1910   - undeclared rule case names default to numbers 1, 2, 3, ...;
  1911   - added 'print_induct_rules' (covered by help item in recent Proof
  1912     General versions);
  1913   - moved induct/cases attributes to Pure, methods to Provers;
  1914   - generic method setup instantiated for FOL and HOL;
  1915 
  1916 * Pure: support multiple simultaneous goal statements, for example
  1917 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  1918 meta-level mechanism, this acts as if several individual goals had
  1919 been stated separately; in particular common proof methods need to be
  1920 repeated in order to cover all claims; note that a single elimination
  1921 step is *not* sufficient to establish the two conjunctions, so this
  1922 fails:
  1923 
  1924   assume "A & B" then have A and B ..   (*".." fails*)
  1925 
  1926 better use "obtain" in situations as above; alternative refer to
  1927 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  1928 
  1929 * Pure: proper integration with ``locales''; unlike the original
  1930 version by Florian Kammller, Isar locales package high-level proof
  1931 contexts rather than raw logical ones (e.g. we admit to include
  1932 attributes everywhere); operations on locales include merge and
  1933 rename; support for implicit arguments (``structures''); simultaneous
  1934 type-inference over imports and text; see also HOL/ex/Locales.thy for
  1935 some examples;
  1936 
  1937 * Pure: the following commands have been ``localized'', supporting a
  1938 target locale specification "(in name)": 'lemma', 'theorem',
  1939 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  1940 stored both within the locale and at the theory level (exported and
  1941 qualified by the locale name);
  1942 
  1943 * Pure: theory goals may now be specified in ``long'' form, with
  1944 ad-hoc contexts consisting of arbitrary locale elements. for example
  1945 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  1946 definitions may be given, too); the result is a meta-level rule with
  1947 the context elements being discharged in the obvious way;
  1948 
  1949 * Pure: new proof command 'using' allows to augment currently used
  1950 facts after a goal statement ('using' is syntactically analogous to
  1951 'apply', but acts on the goal's facts only); this allows chained facts
  1952 to be separated into parts given before and after a claim, as in
  1953 ``from a and b have C using d and e <proof>'';
  1954 
  1955 * Pure: renamed "antecedent" case to "rule_context";
  1956 
  1957 * Pure: new 'judgment' command records explicit information about the
  1958 object-logic embedding (used by several tools internally); no longer
  1959 use hard-wired "Trueprop";
  1960 
  1961 * Pure: added 'corollary' command;
  1962 
  1963 * Pure: fixed 'token_translation' command;
  1964 
  1965 * Pure: removed obsolete 'exported' attribute;
  1966 
  1967 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  1968 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  1969 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  1970 
  1971 * Pure: method 'atomize' presents local goal premises as object-level
  1972 statements (atomic meta-level propositions); setup controlled via
  1973 rewrite rules declarations of 'atomize' attribute; example
  1974 application: 'induct' method with proper rule statements in improper
  1975 proof *scripts*;
  1976 
  1977 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  1978 now consider the syntactic context of assumptions, giving a better
  1979 chance to get type-inference of the arguments right (this is
  1980 especially important for locales);
  1981 
  1982 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  1983 mode;
  1984 
  1985 * Pure/obtain: the formal conclusion "thesis", being marked as
  1986 ``internal'', may no longer be reference directly in the text;
  1987 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  1988 situations;
  1989 
  1990 * Pure: generic 'sym' attribute which declares a rule both as pure
  1991 'elim?' and for the 'symmetric' operation;
  1992 
  1993 * Pure: marginal comments ``--'' may now occur just anywhere in the
  1994 text; the fixed correlation with particular command syntax has been
  1995 discontinued;
  1996 
  1997 * Pure: new method 'rules' is particularly well-suited for proof
  1998 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  1999 but often produces more compact proof terms with less detours;
  2000 
  2001 * Pure/Provers/classical: simplified integration with pure rule
  2002 attributes and methods; the classical "intro?/elim?/dest?"
  2003 declarations coincide with the pure ones; the "rule" method no longer
  2004 includes classically swapped intros; "intro" and "elim" methods no
  2005 longer pick rules from the context; also got rid of ML declarations
  2006 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2007 INCOMPATIBILITY;
  2008 
  2009 * Provers/classical: attribute 'swapped' produces classical inversions
  2010 of introduction rules;
  2011 
  2012 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2013 rules instead of full simplifier context; 'iff' attribute handles
  2014 conditional rules;
  2015 
  2016 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2017 
  2018 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2019 "(permissive)" option to recover old behavior;
  2020 
  2021 * HOL: 'inductive' no longer features separate (collective) attributes
  2022 for 'intros' (was found too confusing);
  2023 
  2024 * HOL: properly declared induction rules less_induct and
  2025 wf_induct_rule;
  2026 
  2027 
  2028 *** HOL ***
  2029 
  2030 * HOL: moved over to sane numeral syntax; the new policy is as
  2031 follows:
  2032 
  2033   - 0 and 1 are polymorphic constants, which are defined on any
  2034   numeric type (nat, int, real etc.);
  2035 
  2036   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2037   binary representation internally;
  2038 
  2039   - type nat has special constructor Suc, and generally prefers Suc 0
  2040   over 1::nat and Suc (Suc 0) over 2::nat;
  2041 
  2042 This change may cause significant problems of INCOMPATIBILITY; here
  2043 are some hints on converting existing sources:
  2044 
  2045   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2046   entities, so expressions involving "-" (unary or binary minus) need
  2047   to be spaced properly;
  2048 
  2049   - existing occurrences of "1" may need to be constraint "1::nat" or
  2050   even replaced by Suc 0; similar for old "2";
  2051 
  2052   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  2053 
  2054   - remove all special provisions on numerals in proofs;
  2055 
  2056 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  2057 representation (depends on bin_arith_simps in the default context);
  2058 
  2059 * HOL: symbolic syntax for x^2 (numeral 2);
  2060 
  2061 * HOL: the class of all HOL types is now called "type" rather than
  2062 "term"; INCOMPATIBILITY, need to adapt references to this type class
  2063 in axclass/classes, instance/arities, and (usually rare) occurrences
  2064 in typings (of consts etc.); internally the class is called
  2065 "HOL.type", ML programs should refer to HOLogic.typeS;
  2066 
  2067 * HOL/record package improvements:
  2068   - new derived operations "fields" to build a partial record section,
  2069     "extend" to promote a fixed record to a record scheme, and
  2070     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  2071     declared as simp by default;
  2072   - shared operations ("more", "fields", etc.) now need to be always
  2073     qualified) --- potential INCOMPATIBILITY;
  2074   - removed "make_scheme" operations (use "make" with "extend") --
  2075     INCOMPATIBILITY;
  2076   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  2077   - provides cases/induct rules for use with corresponding Isar
  2078     methods (for concrete records, record schemes, concrete more
  2079     parts, and schematic more parts -- in that order);
  2080   - internal definitions directly based on a light-weight abstract
  2081     theory of product types over typedef rather than datatype;
  2082 
  2083 * HOL: generic code generator for generating executable ML code from
  2084 specifications; specific support for HOL constructs such as inductive
  2085 datatypes and sets, as well as recursive functions; can be invoked
  2086 via 'generate_code' theory section;
  2087 
  2088 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  2089 
  2090 * HOL: consolidated and renamed several theories.  In particular:
  2091         Ord.thy has been absorbed into HOL.thy
  2092         String.thy has been absorbed into List.thy
  2093 
  2094 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  2095 (beware of argument permutation!);
  2096 
  2097 * HOL: linorder_less_split superseded by linorder_cases;
  2098 
  2099 * HOL/List: "nodups" renamed to "distinct";
  2100 
  2101 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  2102 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  2103   - Ex_def has changed, now need to use some_eq_ex
  2104 
  2105 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  2106 in this (rare) case use:
  2107 
  2108   delSWrapper "split_all_tac"
  2109   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  2110 
  2111 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  2112 MAY FAIL;
  2113 
  2114 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  2115 Isabelle's type classes, ^ on functions and relations has too general
  2116 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  2117 necessary to attach explicit type constraints;
  2118 
  2119 * HOL/Relation: the prefix name of the infix "O" has been changed from
  2120 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  2121 renamed accordingly (eg "compI" -> "rel_compI").
  2122 
  2123 * HOL: syntax translations now work properly with numerals and records
  2124 expressions;
  2125 
  2126 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  2127 of "lam" -- INCOMPATIBILITY;
  2128 
  2129 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  2130 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  2131 renamed "Product_Type.unit";
  2132 
  2133 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  2134 
  2135 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  2136 the "cases" method);
  2137 
  2138 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  2139 Florian Kammller);
  2140 
  2141 * HOL/IMP: updated and converted to new-style theory format; several
  2142 parts turned into readable document, with proper Isar proof texts and
  2143 some explanations (by Gerwin Klein);
  2144 
  2145 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  2146 
  2147 * HOL-Hyperreal is now a logic image;
  2148 
  2149 
  2150 *** HOLCF ***
  2151 
  2152 * Isar: consts/constdefs supports mixfix syntax for continuous
  2153 operations;
  2154 
  2155 * Isar: domain package adapted to new-style theory format, e.g. see
  2156 HOLCF/ex/Dnat.thy;
  2157 
  2158 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  2159 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  2160 lift.induct_tac, always use UU instead of Undef;
  2161 
  2162 * HOLCF/IMP: updated and converted to new-style theory;
  2163 
  2164 
  2165 *** ZF ***
  2166 
  2167 * Isar: proper integration of logic-specific tools and packages,
  2168 including theory commands '(co)inductive', '(co)datatype',
  2169 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  2170 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  2171 
  2172 * theory Main no longer includes AC; for the Axiom of Choice, base
  2173 your theory on Main_ZFC;
  2174 
  2175 * the integer library now covers quotients and remainders, with many
  2176 laws relating division to addition, multiplication, etc.;
  2177 
  2178 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  2179 typeless version of the formalism;
  2180 
  2181 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  2182 format;
  2183 
  2184 * ZF/Induct: new directory for examples of inductive definitions,
  2185 including theory Multiset for multiset orderings; converted to
  2186 new-style theory format;
  2187 
  2188 * ZF: many new theorems about lists, ordinals, etc.;
  2189 
  2190 
  2191 *** General ***
  2192 
  2193 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  2194 variable proof controls level of detail: 0 = no proofs (only oracle
  2195 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  2196 also ref manual for further ML interfaces;
  2197 
  2198 * Pure/axclass: removed obsolete ML interface
  2199 goal_subclass/goal_arity;
  2200 
  2201 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  2202 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  2203 separate tokens, so expressions involving minus need to be spaced
  2204 properly;
  2205 
  2206 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  2207 rather than "infixl" or "infixr";
  2208 
  2209 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  2210 sort constraint specifications in type inference; e.g. "x::_::foo"
  2211 ensures that the type of "x" is of sort "foo" (but not necessarily a
  2212 type variable);
  2213 
  2214 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  2215 control output of nested => (types); the default behavior is
  2216 "type_brackets";
  2217 
  2218 * Pure/syntax: builtin parse translation for "_constify" turns valued
  2219 tokens into AST constants;
  2220 
  2221 * Pure/syntax: prefer later declarations of translations and print
  2222 translation functions; potential INCOMPATIBILITY: need to reverse
  2223 multiple declarations for same syntax element constant;
  2224 
  2225 * Pure/show_hyps reset by default (in accordance to existing Isar
  2226 practice);
  2227 
  2228 * Provers/classical: renamed addaltern to addafter, addSaltern to
  2229 addSafter;
  2230 
  2231 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  2232 as well;
  2233 
  2234 * system: tested support for MacOS X; should be able to get Isabelle +
  2235 Proof General to work in a plain Terminal after installing Poly/ML
  2236 (e.g. from the Isabelle distribution area) and GNU bash alone
  2237 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  2238 support requires further installations, e.g. from
  2239 http://fink.sourceforge.net/);
  2240 
  2241 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  2242 
  2243 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  2244 of 40 MB), cf. ML_OPTIONS;
  2245 
  2246 * system: Proof General keywords specification is now part of the
  2247 Isabelle distribution (see etc/isar-keywords.el);
  2248 
  2249 * system: support for persistent Proof General sessions (refrain from
  2250 outdating all loaded theories on startup); user may create writable
  2251 logic images like this: ``isabelle -q HOL Test'';
  2252 
  2253 * system: smart selection of Isabelle process versus Isabelle
  2254 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  2255 run both "isabelle" and "Isabelle" even if file names are badly
  2256 damaged (executable inspects the case of the first letter of its own
  2257 name); added separate "isabelle-process" and "isabelle-interface";
  2258 
  2259 * system: refrain from any attempt at filtering input streams; no
  2260 longer support ``8bit'' encoding of old isabelle font, instead proper
  2261 iso-latin characters may now be used; the related isatools
  2262 "symbolinput" and "nonascii" have disappeared as well;
  2263 
  2264 * system: removed old "xterm" interface (the print modes "xterm" and
  2265 "xterm_color" are still available for direct use in a suitable
  2266 terminal);
  2267 
  2268 
  2269 
  2270 New in Isabelle99-2 (February 2001)
  2271 -----------------------------------
  2272 
  2273 *** Overview of INCOMPATIBILITIES ***
  2274 
  2275 * HOL: please note that theories in the Library and elsewhere often use the
  2276 new-style (Isar) format; to refer to their theorems in an ML script you must
  2277 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  2278 
  2279 * HOL: inductive package no longer splits induction rule aggressively,
  2280 but only as far as specified by the introductions given; the old
  2281 format may be recovered via ML function complete_split_rule or attribute
  2282 'split_rule (complete)';
  2283 
  2284 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  2285 gfp_Tarski to gfp_unfold;
  2286 
  2287 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  2288 
  2289 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  2290 relation); infix "^^" has been renamed "``"; infix "``" has been
  2291 renamed "`"; "univalent" has been renamed "single_valued";
  2292 
  2293 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  2294 operation;
  2295 
  2296 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  2297 
  2298 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  2299 
  2300 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  2301 consequence, it is no longer monotonic wrt. the local goal context
  2302 (which is now passed through the inductive cases);
  2303 
  2304 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  2305 \<gg> to \<ggreater>;
  2306 
  2307 
  2308 *** Document preparation ***
  2309 
  2310 * \isabellestyle{NAME} selects version of Isabelle output (currently
  2311 available: are "it" for near math-mode best-style output, "sl" for
  2312 slanted text style, and "tt" for plain type-writer; if no
  2313 \isabellestyle command is given, output is according to slanted
  2314 type-writer);
  2315 
  2316 * support sub/super scripts (for single symbols only), input syntax is
  2317 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  2318 
  2319 * some more standard symbols; see Appendix A of the system manual for
  2320 the complete list of symbols defined in isabellesym.sty;
  2321 
  2322 * improved isabelle style files; more abstract symbol implementation
  2323 (should now use \isamath{...} and \isatext{...} in custom symbol
  2324 definitions);
  2325 
  2326 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  2327 state; Note that presentation of goal states does not conform to
  2328 actual human-readable proof documents.  Please do not include goal
  2329 states into document output unless you really know what you are doing!
  2330 
  2331 * proper indentation of antiquoted output with proportional LaTeX
  2332 fonts;
  2333 
  2334 * no_document ML operator temporarily disables LaTeX document
  2335 generation;
  2336 
  2337 * isatool unsymbolize tunes sources for plain ASCII communication;
  2338 
  2339 
  2340 *** Isar ***
  2341 
  2342 * Pure: Isar now suffers initial goal statements to contain unbound
  2343 schematic variables (this does not conform to actual readable proof
  2344 documents, due to unpredictable outcome and non-compositional proof
  2345 checking); users who know what they are doing may use schematic goals
  2346 for Prolog-style synthesis of proven results;
  2347 
  2348 * Pure: assumption method (an implicit finishing) now handles actual
  2349 rules as well;
  2350 
  2351 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  2352 initial goal, declare "that" only as Pure intro (only for single
  2353 steps); the "that" rule assumption may now be involved in implicit
  2354 finishing, thus ".." becomes a feasible for trivial obtains;
  2355 
  2356 * Pure: default proof step now includes 'intro_classes'; thus trivial
  2357 instance proofs may be performed by "..";
  2358 
  2359 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  2360 statements as well;
  2361 
  2362 * Pure: more robust selection of calculational rules;
  2363 
  2364 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  2365 rule (as well as the assumption rule);
  2366 
  2367 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  2368 lemmas, using the graph browser tool;
  2369 
  2370 * Pure: predict failure of "show" in interactive mode;
  2371 
  2372 * Pure: 'thms_containing' now takes actual terms as arguments;
  2373 
  2374 * HOL: improved method 'induct' --- now handles non-atomic goals
  2375 (potential INCOMPATIBILITY); tuned error handling;
  2376 
  2377 * HOL: cases and induct rules now provide explicit hints about the
  2378 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  2379 any remaining facts are inserted into the goal verbatim;
  2380 
  2381 * HOL: local contexts (aka cases) may now contain term bindings as
  2382 well; the 'cases' and 'induct' methods new provide a ?case binding for
  2383 the result to be shown in each case;
  2384 
  2385 * HOL: added 'recdef_tc' command;
  2386 
  2387 * isatool convert assists in eliminating legacy ML scripts;
  2388 
  2389 
  2390 *** HOL ***
  2391 
  2392 * HOL/Library: a collection of generic theories to be used together
  2393 with main HOL; the theory loader path already includes this directory
  2394 by default; the following existing theories have been moved here:
  2395 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  2396 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  2397 
  2398 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  2399 modelling and verification task performed in Isabelle/HOL +
  2400 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  2401 
  2402 * HOL/Algebra: special summation operator SUM no longer exists, it has
  2403 been replaced by setsum; infix 'assoc' now has priority 50 (like
  2404 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  2405 'domain', this makes the theory consistent with mathematical
  2406 literature;
  2407 
  2408 * HOL basics: added overloaded operations "inverse" and "divide"
  2409 (infix "/"), syntax for generic "abs" operation, generic summation
  2410 operator \<Sum>;
  2411 
  2412 * HOL/typedef: simplified package, provide more useful rules (see also
  2413 HOL/subset.thy);
  2414 
  2415 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  2416 now expressed as a proper nested rule (old-style tactic scripts may
  2417 require atomize_strip_tac to cope with non-atomic premises);
  2418 
  2419 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  2420 to "split_conv" (old name still available for compatibility);
  2421 
  2422 * HOL: improved concrete syntax for strings (e.g. allows translation
  2423 rules with string literals);
  2424 
  2425 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  2426  and Fleuriot's mechanization of analysis, including the transcendental
  2427  functions for the reals;
  2428 
  2429 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  2430 
  2431 
  2432 *** CTT ***
  2433 
  2434 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  2435 "lam" is displayed as TWO lambda-symbols
  2436 
  2437 * CTT: theory Main now available, containing everything (that is, Bool
  2438 and Arith);
  2439 
  2440 
  2441 *** General ***
  2442 
  2443 * Pure: the Simplifier has been implemented properly as a derived rule
  2444 outside of the actual kernel (at last!); the overall performance
  2445 penalty in practical applications is about 50%, while reliability of
  2446 the Isabelle inference kernel has been greatly improved;
  2447 
  2448 * print modes "brackets" and "no_brackets" control output of nested =>
  2449 (types) and ==> (props); the default behaviour is "brackets";
  2450 
  2451 * Provers: fast_tac (and friends) now handle actual object-logic rules
  2452 as assumptions as well;
  2453 
  2454 * system: support Poly/ML 4.0;
  2455 
  2456 * system: isatool install handles KDE version 1 or 2;
  2457 
  2458 
  2459 
  2460 New in Isabelle99-1 (October 2000)
  2461 ----------------------------------
  2462 
  2463 *** Overview of INCOMPATIBILITIES ***
  2464 
  2465 * HOL: simplification of natural numbers is much changed; to partly
  2466 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  2467 issue the following ML commands:
  2468 
  2469   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  2470   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  2471 
  2472 * HOL: simplification no longer dives into case-expressions; this is
  2473 controlled by "t.weak_case_cong" for each datatype t;
  2474 
  2475 * HOL: nat_less_induct renamed to less_induct;
  2476 
  2477 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  2478 fixsome to patch .thy and .ML sources automatically;
  2479 
  2480   select_equality  -> some_equality
  2481   select_eq_Ex     -> some_eq_ex
  2482   selectI2EX       -> someI2_ex
  2483   selectI2         -> someI2
  2484   selectI          -> someI
  2485   select1_equality -> some1_equality
  2486   Eps_sym_eq       -> some_sym_eq_trivial
  2487   Eps_eq           -> some_eq_trivial
  2488 
  2489 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  2490 
  2491 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  2492 instead);
  2493 
  2494 * HOL: the recursion equations generated by 'recdef' are now called
  2495 f.simps instead of f.rules;
  2496 
  2497 * HOL: qed_spec_mp now also handles bounded ALL as well;
  2498 
  2499 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  2500 sometimes be needed;
  2501 
  2502 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  2503 
  2504 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  2505 
  2506 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  2507 product is now "<*>" instead of "Times"; the lexicographic product is
  2508 now "<*lex*>" instead of "**";
  2509 
  2510 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  2511 of main HOL, but was unused); better use HOL's datatype package;
  2512 
  2513 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  2514 the old syntax may be recovered as follows:
  2515 
  2516   syntax (symbols)
  2517     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  2518       (infixl "\\<oplus>" 100)
  2519 
  2520 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  2521 
  2522 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  2523 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  2524 internally;
  2525 
  2526 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  2527 changed from A/r to A//r;
  2528 
  2529 * ZF: new treatment of arithmetic (nat & int) may break some old
  2530 proofs;
  2531 
  2532 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  2533 rulify -> rule_format, elimify -> elim_format, ...);
  2534 
  2535 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2536 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  2537 should have to change intro!! to intro? only); replaced "delrule" by
  2538 "rule del";
  2539 
  2540 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  2541 
  2542 * Provers: strengthened force_tac by using new first_best_tac;
  2543 
  2544 * LaTeX document preparation: several changes of isabelle.sty (see
  2545 lib/texinputs);
  2546 
  2547 
  2548 *** Document preparation ***
  2549 
  2550 * formal comments (text blocks etc.) in new-style theories may now
  2551 contain antiquotations of thm/prop/term/typ/text to be presented
  2552 according to latex print mode; concrete syntax is like this:
  2553 @{term[show_types] "f(x) = a + x"};
  2554 
  2555 * isatool mkdir provides easy setup of Isabelle session directories,
  2556 including proper document sources;
  2557 
  2558 * generated LaTeX sources are now deleted after successful run
  2559 (isatool document -c); may retain a copy somewhere else via -D option
  2560 of isatool usedir;
  2561 
  2562 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  2563 style files, achieving self-contained LaTeX sources and simplifying
  2564 LaTeX debugging;
  2565 
  2566 * old-style theories now produce (crude) LaTeX output as well;
  2567 
  2568 * browser info session directories are now self-contained (may be put
  2569 on WWW server seperately); improved graphs of nested sessions; removed
  2570 graph for 'all sessions';
  2571 
  2572 * several improvements in isabelle style files; \isabellestyle{it}
  2573 produces fake math mode output; \isamarkupheader is now \section by
  2574 default; see lib/texinputs/isabelle.sty etc.;
  2575 
  2576 
  2577 *** Isar ***
  2578 
  2579 * Isar/Pure: local results and corresponding term bindings are now
  2580 subject to Hindley-Milner polymorphism (similar to ML); this
  2581 accommodates incremental type-inference very nicely;
  2582 
  2583 * Isar/Pure: new derived language element 'obtain' supports
  2584 generalized existence reasoning;
  2585 
  2586 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  2587 support accumulation of results, without applying any rules yet;
  2588 useful to collect intermediate results without explicit name
  2589 references, and for use with transitivity rules with more than 2
  2590 premises;
  2591 
  2592 * Isar/Pure: scalable support for case-analysis type proofs: new
  2593 'case' language element refers to local contexts symbolically, as
  2594 produced by certain proof methods; internally, case names are attached
  2595 to theorems as "tags";
  2596 
  2597 * Isar/Pure: theory command 'hide' removes declarations from
  2598 class/type/const name spaces;
  2599 
  2600 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  2601 indicate potential overloading;
  2602 
  2603 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  2604 
  2605 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  2606 "{a,b,c}" instead of {a,b,c};
  2607 
  2608 * Isar/Pure now provides its own version of intro/elim/dest
  2609 attributes; useful for building new logics, but beware of confusion
  2610 with the version in Provers/classical;
  2611 
  2612 * Isar/Pure: the local context of (non-atomic) goals is provided via
  2613 case name 'antecedent';
  2614 
  2615 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  2616 to the current context is now done automatically);
  2617 
  2618 * Isar/Pure: theory command 'method_setup' provides a simple interface
  2619 for definining proof methods in ML;
  2620 
  2621 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2622 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  2623 most cases, one should have to change intro!! to intro? only);
  2624 replaced "delrule" by "rule del";
  2625 
  2626 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  2627 'symmetric' attribute (the latter supercedes [RS sym]);
  2628 
  2629 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  2630 method modifier); 'simp' method: 'only:' modifier removes loopers as
  2631 well (including splits);
  2632 
  2633 * Isar/Provers: Simplifier and Classical methods now support all kind
  2634 of modifiers used in the past, including 'cong', 'iff', etc.
  2635 
  2636 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  2637 of Simplifier and Classical reasoner);
  2638 
  2639 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  2640 now support named cases; major packages (inductive, datatype, primrec,
  2641 recdef) support case names and properly name parameters;
  2642 
  2643 * Isar/HOL: new transitivity rules for substitution in inequalities --
  2644 monotonicity conditions are extracted to be proven at end of
  2645 calculations;
  2646 
  2647 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  2648 method anyway;
  2649 
  2650 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  2651 split_if split_if_asm; datatype package provides theorems foo.splits =
  2652 foo.split foo.split_asm for each datatype;
  2653 
  2654 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  2655 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  2656 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  2657 use "(cases (simplified))" method in proper proof texts);
  2658 
  2659 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  2660 
  2661 * Isar: names of theorems etc. may be natural numbers as well;
  2662 
  2663 * Isar: 'pr' command: optional arguments for goals_limit and
  2664 ProofContext.prems_limit; no longer prints theory contexts, but only
  2665 proof states;
  2666 
  2667 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  2668 additional print modes to be specified; e.g. "pr(latex)" will print
  2669 proof state according to the Isabelle LaTeX style;
  2670 
  2671 * Isar: improved support for emulating tactic scripts, including proof
  2672 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  2673 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  2674 (for HOL datatypes);
  2675 
  2676 * Isar: simplified (more robust) goal selection of proof methods: 1st
  2677 goal, all goals, or explicit goal specifier (tactic emulation); thus
  2678 'proof method scripts' have to be in depth-first order;
  2679 
  2680 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  2681 
  2682 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  2683 should instead use individual commands for printing items
  2684 (print_commands, print_methods etc.);
  2685 
  2686 * Isar: added 'nothing' --- the empty list of theorems;
  2687 
  2688 
  2689 *** HOL ***
  2690 
  2691 * HOL/MicroJava: formalization of a fragment of Java, together with a
  2692 corresponding virtual machine and a specification of its bytecode
  2693 verifier and a lightweight bytecode verifier, including proofs of
  2694 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  2695 Cornelia Pusch (see also the homepage of project Bali at
  2696 http://isabelle.in.tum.de/Bali/);
  2697 
  2698 * HOL/Algebra: new theory of rings and univariate polynomials, by
  2699 Clemens Ballarin;
  2700 
  2701 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  2702 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  2703 Rasmussen;
  2704 
  2705 * HOL/Lattice: fundamental concepts of lattice theory and order
  2706 structures, including duals, properties of bounds versus algebraic
  2707 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  2708 Theorem for complete lattices etc.; may also serve as a demonstration
  2709 for abstract algebraic reasoning using axiomatic type classes, and
  2710 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  2711 
  2712 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  2713 von Oheimb;
  2714 
  2715 * HOL/IMPP: extension of IMP with local variables and mutually
  2716 recursive procedures, by David von Oheimb;
  2717 
  2718 * HOL/Lambda: converted into new-style theory and document;
  2719 
  2720 * HOL/ex/Multiquote: example of multiple nested quotations and
  2721 anti-quotations -- basically a generalized version of de-Bruijn
  2722 representation; very useful in avoiding lifting of operations;
  2723 
  2724 * HOL/record: added general record equality rule to simpset; fixed
  2725 select-update simplification procedure to handle extended records as
  2726 well; admit "r" as field name;
  2727 
  2728 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  2729 other numeric types and also as the identity of groups, rings, etc.;
  2730 
  2731 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  2732 Types nat and int belong to this axclass;
  2733 
  2734 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  2735    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  2736    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  2737   two terms #m*u and #n*u are replaced by #(m+n)*u
  2738     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  2739   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  2740     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  2741 
  2742 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  2743 powerful prover for predicate logic but knows nothing of clasets; see
  2744 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  2745 
  2746 * HOL: new version of "case_tac" subsumes both boolean case split and
  2747 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  2748 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  2749 
  2750 * HOL: simplification no longer dives into case-expressions: only the
  2751 selector expression is simplified, but not the remaining arms; to
  2752 enable full simplification of case-expressions for datatype t, you may
  2753 remove t.weak_case_cong from the simpset, either globally (Delcongs
  2754 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  2755 
  2756 * HOL/recdef: the recursion equations generated by 'recdef' for
  2757 function 'f' are now called f.simps instead of f.rules; if all
  2758 termination conditions are proved automatically, these simplification
  2759 rules are added to the simpset, as in primrec; rules may be named
  2760 individually as well, resulting in a separate list of theorems for
  2761 each equation;
  2762 
  2763 * HOL/While is a new theory that provides a while-combinator. It
  2764 permits the definition of tail-recursive functions without the
  2765 provision of a termination measure. The latter is necessary once the
  2766 invariant proof rule for while is applied.
  2767 
  2768 * HOL: new (overloaded) notation for the set of elements below/above
  2769 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  2770 
  2771 * HOL: theorems impI, allI, ballI bound as "strip";
  2772 
  2773 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  2774 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  2775 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  2776 
  2777 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  2778 
  2779 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  2780 main HOL, but was unused);
  2781 
  2782 * HOL: fewer consts declared as global (e.g. have to refer to
  2783 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  2784 
  2785 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  2786 in case of overlap with user translations (e.g. judgements over
  2787 tuples); (note that the underlying logical represenation is still
  2788 bogus);
  2789 
  2790 
  2791 *** ZF ***
  2792 
  2793 * ZF: simplification automatically cancels common terms in arithmetic
  2794 expressions over nat and int;
  2795 
  2796 * ZF: new treatment of nat to minimize type-checking: all operators
  2797 coerce their operands to a natural number using the function natify,
  2798 making the algebraic laws unconditional;
  2799 
  2800 * ZF: as above, for int: operators coerce their operands to an integer
  2801 using the function intify;
  2802 
  2803 * ZF: the integer library now contains many of the usual laws for the
  2804 orderings, including $<=, and monotonicity laws for $+ and $*;
  2805 
  2806 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  2807 simplification;
  2808 
  2809 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  2810 to the simplifier and classical reasoner simultaneously;
  2811 
  2812 
  2813 *** General ***
  2814 
  2815 * Provers: blast_tac now handles actual object-logic rules as
  2816 assumptions; note that auto_tac uses blast_tac internally as well;
  2817 
  2818 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  2819 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  2820 
  2821 * Provers: delrules now handles destruct rules as well (no longer need
  2822 explicit make_elim);
  2823 
  2824 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  2825   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2826 use instead the strong form,
  2827   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2828 in HOL, FOL and ZF the function cla_make_elim will create such rules
  2829 from destruct-rules;
  2830 
  2831 * Provers: Simplifier.easy_setup provides a fast path to basic
  2832 Simplifier setup for new object-logics;
  2833 
  2834 * Pure: AST translation rules no longer require constant head on LHS;
  2835 
  2836 * Pure: improved name spaces: ambiguous output is qualified; support
  2837 for hiding of names;
  2838 
  2839 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  2840 XSYMBOL_HOME; no longer need to do manual configuration in most
  2841 situations;
  2842 
  2843 * system: compression of ML heaps images may now be controlled via -c
  2844 option of isabelle and isatool usedir (currently only observed by
  2845 Poly/ML);
  2846 
  2847 * system: isatool installfonts may handle X-Symbol fonts as well (very
  2848 useful for remote X11);
  2849 
  2850 * system: provide TAGS file for Isabelle sources;
  2851 
  2852 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  2853 order;
  2854 
  2855 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  2856 timing flag supersedes proof_timing and Toplevel.trace;
  2857 
  2858 * ML: new combinators |>> and |>>> for incremental transformations
  2859 with secondary results (e.g. certain theory extensions):
  2860 
  2861 * ML: PureThy.add_defs gets additional argument to indicate potential
  2862 overloading (usually false);
  2863 
  2864 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  2865 results;
  2866 
  2867 
  2868 
  2869 New in Isabelle99 (October 1999)
  2870 --------------------------------
  2871 
  2872 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2873 
  2874 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  2875 are no longer simplified.  (This allows the simplifier to unfold recursive
  2876 functional programs.)  To restore the old behaviour, declare
  2877 
  2878     Delcongs [if_weak_cong];
  2879 
  2880 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  2881 complement;
  2882 
  2883 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  2884 
  2885 * HOL/datatype: mutual_induct_tac no longer exists --
  2886   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  2887 
  2888 * HOL/typedef: fixed type inference for representing set; type
  2889 arguments now have to occur explicitly on the rhs as type constraints;
  2890 
  2891 * ZF: The con_defs part of an inductive definition may no longer refer
  2892 to constants declared in the same theory;
  2893 
  2894 * HOL, ZF: the function mk_cases, generated by the inductive
  2895 definition package, has lost an argument.  To simplify its result, it
  2896 uses the default simpset instead of a supplied list of theorems.
  2897 
  2898 * HOL/List: the constructors of type list are now Nil and Cons;
  2899 
  2900 * Simplifier: the type of the infix ML functions
  2901         setSSolver addSSolver setSolver addSolver
  2902 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  2903 for packaging solvers. A solver is created via
  2904         mk_solver: string -> (thm list -> int -> tactic) -> solver
  2905 where the string argument is only a comment.
  2906 
  2907 
  2908 *** Proof tools ***
  2909 
  2910 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  2911 decision procedure for linear arithmetic. Currently it is used for
  2912 types `nat', `int', and `real' in HOL (see below); it can, should and
  2913 will be instantiated for other types and logics as well.
  2914 
  2915 * The simplifier now accepts rewrite rules with flexible heads, eg
  2916      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  2917   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  2918   matching.
  2919 
  2920 
  2921 *** General ***
  2922 
  2923 * New Isabelle/Isar subsystem provides an alternative to traditional
  2924 tactical theorem proving; together with the ProofGeneral/isar user
  2925 interface it offers an interactive environment for developing human
  2926 readable proof documents (Isar == Intelligible semi-automated
  2927 reasoning); for further information see isatool doc isar-ref,
  2928 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  2929 
  2930 * improved and simplified presentation of theories: better HTML markup
  2931 (including colors), graph views in several sizes; isatool usedir now
  2932 provides a proper interface for user theories (via -P option); actual
  2933 document preparation based on (PDF)LaTeX is available as well (for
  2934 new-style theories only); see isatool doc system for more information;
  2935 
  2936 * native support for Proof General, both for classic Isabelle and
  2937 Isabelle/Isar;
  2938 
  2939 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  2940 using the graph browser tool;
  2941 
  2942 * Isabelle manuals now also available as PDF;
  2943 
  2944 * theory loader rewritten from scratch (may not be fully
  2945 bug-compatible); old loadpath variable has been replaced by show_path,
  2946 add_path, del_path, reset_path functions; new operations such as
  2947 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  2948 isatool doc ref);
  2949 
  2950 * improved isatool install: option -k creates KDE application icon,
  2951 option -p DIR installs standalone binaries;
  2952 
  2953 * added ML_PLATFORM setting (useful for cross-platform installations);
  2954 more robust handling of platform specific ML images for SML/NJ;
  2955 
  2956 * the settings environment is now statically scoped, i.e. it is never
  2957 created again in sub-processes invoked from isabelle, isatool, or
  2958 Isabelle;
  2959 
  2960 * path element specification '~~' refers to '$ISABELLE_HOME';
  2961 
  2962 * in locales, the "assumes" and "defines" parts may be omitted if
  2963 empty;
  2964 
  2965 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  2966 long arrows);
  2967 
  2968 * new print_mode "HTML";
  2969 
  2970 * new flag show_tags controls display of tags of theorems (which are
  2971 basically just comments that may be attached by some tools);
  2972 
  2973 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  2974 mode and goal output format:
  2975 
  2976 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  2977 244c244
  2978 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  2979 ---
  2980 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  2981 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  2982 181c181
  2983 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  2984 ---
  2985 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  2986 
  2987 * function bind_thms stores lists of theorems (cf. bind_thm);
  2988 
  2989 * new shorthand tactics ftac, eatac, datac, fatac;
  2990 
  2991 * qed (and friends) now accept "" as result name; in that case the
  2992 theorem is not stored, but proper checks and presentation of the
  2993 result still apply;
  2994 
  2995 * theorem database now also indexes constants "Trueprop", "all",
  2996 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  2997 
  2998 
  2999 *** HOL ***
  3000 
  3001 ** HOL arithmetic **
  3002 
  3003 * There are now decision procedures for linear arithmetic over nat and
  3004 int:
  3005 
  3006 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3007 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3008 are treated as atomic; subformulae not involving type `nat' or `int'
  3009 are ignored; quantified subformulae are ignored unless they are
  3010 positive universal or negative existential. The tactic has to be
  3011 invoked by hand and can be a little bit slow. In particular, the
  3012 running time is exponential in the number of occurrences of `min' and
  3013 `max', and `-' on `nat'.
  3014 
  3015 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3016 (negated) (in)equalities among the premises and the conclusion into
  3017 account (i.e. no compound formulae) and does not know about `min' and
  3018 `max', and `-' on `nat'. It is fast and is used automatically by the
  3019 simplifier.
  3020 
  3021 NB: At the moment, these decision procedures do not cope with mixed
  3022 nat/int formulae where the two parts interact, such as `m < n ==>
  3023 int(m) < int(n)'.
  3024 
  3025 * HOL/Numeral provides a generic theory of numerals (encoded
  3026 efficiently as bit strings); setup for types nat/int/real is in place;
  3027 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3028 int, existing theories and proof scripts may require a few additional
  3029 type constraints;
  3030 
  3031 * integer division and remainder can now be performed on constant
  3032 arguments;
  3033 
  3034 * many properties of integer multiplication, division and remainder
  3035 are now available;
  3036 
  3037 * An interface to the Stanford Validity Checker (SVC) is available through the
  3038 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3039 are proved automatically.  SVC must be installed separately, and its results
  3040 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3041 invocation of the underlying oracle).  For SVC see
  3042   http://verify.stanford.edu/SVC
  3043 
  3044 * IsaMakefile: the HOL-Real target now builds an actual image;
  3045 
  3046 
  3047 ** HOL misc **
  3048 
  3049 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  3050 (in Isabelle/Isar) -- by Gertrud Bauer;
  3051 
  3052 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  3053 analysis for assembly languages with subtypes;
  3054 
  3055 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  3056 -- avoids syntactic ambiguities and treats state, transition, and
  3057 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  3058 changed syntax and (many) tactics;
  3059 
  3060 * HOL/inductive: Now also handles more general introduction rules such
  3061   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  3062   theorems are now maintained within the theory (maintained via the
  3063   "mono" attribute);
  3064 
  3065 * HOL/datatype: Now also handles arbitrarily branching datatypes
  3066   (using function types) such as
  3067 
  3068   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  3069 
  3070 * HOL/record: record_simproc (part of the default simpset) takes care
  3071 of selectors applied to updated records; record_split_tac is no longer
  3072 part of the default claset; update_defs may now be removed from the
  3073 simpset in many cases; COMPATIBILITY: old behavior achieved by
  3074 
  3075   claset_ref () := claset() addSWrapper record_split_wrapper;
  3076   Delsimprocs [record_simproc]
  3077 
  3078 * HOL/typedef: fixed type inference for representing set; type
  3079 arguments now have to occur explicitly on the rhs as type constraints;
  3080 
  3081 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  3082 names rather than an ML expression;
  3083 
  3084 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  3085 supplied later.  Program schemes can be defined, such as
  3086     "While B C s = (if B s then While B C (C s) else s)"
  3087 where the well-founded relation can be chosen after B and C have been given.
  3088 
  3089 * HOL/List: the constructors of type list are now Nil and Cons;
  3090 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  3091 course, ML tools referring to List.list.op # etc. have to be adapted;
  3092 
  3093 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  3094 disabled by default; run isabelle with option -m HOL to get back to
  3095 the original Gordon/HOL-style output;
  3096 
  3097 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  3098 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  3099 
  3100 * HOL basic syntax simplified (more orthogonal): all variants of
  3101 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  3102 Eps operator is provided as well: "SOME x. P[x]";
  3103 
  3104 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  3105 
  3106 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  3107 thus available for user theories;
  3108 
  3109 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  3110 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  3111 time;
  3112 
  3113 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  3114 several times and then mp;
  3115 
  3116 
  3117 *** LK ***
  3118 
  3119 * the notation <<...>> is now available as a notation for sequences of
  3120 formulas;
  3121 
  3122 * the simplifier is now installed
  3123 
  3124 * the axiom system has been generalized (thanks to Soren Heilmann)
  3125 
  3126 * the classical reasoner now has a default rule database
  3127 
  3128 
  3129 *** ZF ***
  3130 
  3131 * new primrec section allows primitive recursive functions to be given
  3132 directly (as in HOL) over datatypes and the natural numbers;
  3133 
  3134 * new tactics induct_tac and exhaust_tac for induction (or case
  3135 analysis) over datatypes and the natural numbers;
  3136 
  3137 * the datatype declaration of type T now defines the recursor T_rec;
  3138 
  3139 * simplification automatically does freeness reasoning for datatype
  3140 constructors;
  3141 
  3142 * automatic type-inference, with AddTCs command to insert new
  3143 type-checking rules;
  3144 
  3145 * datatype introduction rules are now added as Safe Introduction rules
  3146 to the claset;
  3147 
  3148 * the syntax "if P then x else y" is now available in addition to
  3149 if(P,x,y);
  3150 
  3151 
  3152 *** Internal programming interfaces ***
  3153 
  3154 * tuned simplifier trace output; new flag debug_simp;
  3155 
  3156 * structures Vartab / Termtab (instances of TableFun) offer efficient
  3157 tables indexed by indexname_ord / term_ord (compatible with aconv);
  3158 
  3159 * AxClass.axclass_tac lost the theory argument;
  3160 
  3161 * tuned current_goals_markers semantics: begin / end goal avoids
  3162 printing empty lines;
  3163 
  3164 * removed prs and prs_fn hook, which was broken because it did not
  3165 include \n in its semantics, forcing writeln to add one
  3166 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  3167 string -> unit if you really want to output text without newline;
  3168 
  3169 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  3170 plain output, interface builders may have to enable 'isabelle_font'
  3171 mode to get Isabelle font glyphs as before;
  3172 
  3173 * refined token_translation interface; INCOMPATIBILITY: output length
  3174 now of type real instead of int;
  3175 
  3176 * theory loader actions may be traced via new ThyInfo.add_hook
  3177 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  3178 your own database of information attached to *whole* theories -- as
  3179 opposed to intra-theory data slots offered via TheoryDataFun;
  3180 
  3181 * proper handling of dangling sort hypotheses (at last!);
  3182 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  3183 extra sort hypotheses that can be witnessed from the type signature;
  3184 the force_strip_shyps flag is gone, any remaining shyps are simply
  3185 left in the theorem (with a warning issued by strip_shyps_warning);
  3186 
  3187 
  3188 
  3189 New in Isabelle98-1 (October 1998)
  3190 ----------------------------------
  3191 
  3192 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3193 
  3194 * several changes of automated proof tools;
  3195 
  3196 * HOL: major changes to the inductive and datatype packages, including
  3197 some minor incompatibilities of theory syntax;
  3198 
  3199 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  3200 called `inj_on';
  3201 
  3202 * HOL: removed duplicate thms in Arith:
  3203   less_imp_add_less  should be replaced by  trans_less_add1
  3204   le_imp_add_le      should be replaced by  trans_le_add1
  3205 
  3206 * HOL: unary minus is now overloaded (new type constraints may be
  3207 required);
  3208 
  3209 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  3210 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  3211 now taken as an integer constant.
  3212 
  3213 * Pure: ML function 'theory_of' renamed to 'theory';
  3214 
  3215 
  3216 *** Proof tools ***
  3217 
  3218 * Simplifier:
  3219   1. Asm_full_simp_tac is now more aggressive.
  3220      1. It will sometimes reorient premises if that increases their power to
  3221         simplify.
  3222      2. It does no longer proceed strictly from left to right but may also
  3223         rotate premises to achieve further simplification.
  3224      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  3225      old Asm_full_simp_tac in that it does not rotate premises.
  3226   2. The simplifier now knows a little bit about nat-arithmetic.
  3227 
  3228 * Classical reasoner: wrapper mechanism for the classical reasoner now
  3229 allows for selected deletion of wrappers, by introduction of names for
  3230 wrapper functionals.  This implies that addbefore, addSbefore,
  3231 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  3232 and that adding two tactics with the same name overwrites the first
  3233 one (emitting a warning).
  3234   type wrapper = (int -> tactic) -> (int -> tactic)
  3235   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  3236   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  3237   delWrapper, delSWrapper: claset *  string            -> claset
  3238   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  3239 
  3240 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  3241 semantics; addbefore now affects only the unsafe part of step_tac
  3242 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  3243 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  3244 by Force_tac;
  3245 
  3246 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  3247 compWrapper; added safe wrapper (and access functions for it);
  3248 
  3249 * HOL/split_all_tac is now much faster and fails if there is nothing
  3250 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  3251 and the names of the automatically generated variables have changed.
  3252 split_all_tac has moved within claset() from unsafe wrappers to safe
  3253 wrappers, which means that !!-bound variables are split much more
  3254 aggressively, and safe_tac and clarify_tac now split such variables.
  3255 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  3256 Note: the same holds for record_split_tac, which does the job of
  3257 split_all_tac for record fields.
  3258 
  3259 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  3260 permanently to the default simpset using Addsplits just like
  3261 Addsimps. They can be removed via Delsplits just like
  3262 Delsimps. Lower-case versions are also available.
  3263 
  3264 * HOL/Simplifier: The rule split_if is now part of the default
  3265 simpset. This means that the simplifier will eliminate all occurrences
  3266 of if-then-else in the conclusion of a goal. To prevent this, you can
  3267 either remove split_if completely from the default simpset by
  3268 `Delsplits [split_if]' or remove it in a specific call of the
  3269 simplifier using `... delsplits [split_if]'.  You can also add/delete
  3270 other case splitting rules to/from the default simpset: every datatype
  3271 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  3272 t is the name of the datatype).
  3273 
  3274 * Classical reasoner / Simplifier combination: new force_tac (and
  3275 derivatives Force_tac, force) combines rewriting and classical
  3276 reasoning (and whatever other tools) similarly to auto_tac, but is
  3277 aimed to solve the given subgoal completely.
  3278 
  3279 
  3280 *** General ***
  3281 
  3282 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  3283 and `goalw': the theory is no longer needed as an explicit argument -
  3284 the current theory context is used; assumptions are no longer returned
  3285 at the ML-level unless one of them starts with ==> or !!; it is
  3286 recommended to convert to these new commands using isatool fixgoal
  3287 (backup your sources first!);
  3288 
  3289 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  3290 the current theory context, and 'theory' to lookup stored theories;
  3291 
  3292 * new theory section 'locale' for declaring constants, assumptions and
  3293 definitions that have local scope;
  3294 
  3295 * new theory section 'nonterminals' for purely syntactic types;
  3296 
  3297 * new theory section 'setup' for generic ML setup functions
  3298 (e.g. package initialization);
  3299 
  3300 * the distribution now includes Isabelle icons: see
  3301 lib/logo/isabelle-{small,tiny}.xpm;
  3302 
  3303 * isatool install - install binaries with absolute references to
  3304 ISABELLE_HOME/bin;
  3305 
  3306 * isatool logo -- create instances of the Isabelle logo (as EPS);
  3307 
  3308 * print mode 'emacs' reserved for Isamode;
  3309 
  3310 * support multiple print (ast) translations per constant name;
  3311 
  3312 * theorems involving oracles are now printed with a suffixed [!];
  3313 
  3314 
  3315 *** HOL ***
  3316 
  3317 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  3318 
  3319 * HOL/inductive package reorganized and improved: now supports mutual
  3320 definitions such as
  3321 
  3322   inductive EVEN ODD
  3323     intrs
  3324       null "0 : EVEN"
  3325       oddI "n : EVEN ==> Suc n : ODD"
  3326       evenI "n : ODD ==> Suc n : EVEN"
  3327 
  3328 new theorem list "elims" contains an elimination rule for each of the
  3329 recursive sets; inductive definitions now handle disjunctive premises
  3330 correctly (also ZF);
  3331 
  3332 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  3333 "mutual_induct" no longer exists - the induction rule is always
  3334 contained in "induct";
  3335 
  3336 
  3337 * HOL/datatype package re-implemented and greatly improved: now
  3338 supports mutually recursive datatypes such as
  3339 
  3340   datatype
  3341     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  3342             | SUM ('a aexp) ('a aexp)
  3343             | DIFF ('a aexp) ('a aexp)
  3344             | NUM 'a
  3345   and
  3346     'a bexp = LESS ('a aexp) ('a aexp)
  3347             | AND ('a bexp) ('a bexp)
  3348             | OR ('a bexp) ('a bexp)
  3349 
  3350 as well as indirectly recursive datatypes such as
  3351 
  3352   datatype
  3353     ('a, 'b) term = Var 'a
  3354                   | App 'b ((('a, 'b) term) list)
  3355 
  3356 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  3357 induction on mutually / indirectly recursive datatypes.
  3358 
  3359 Primrec equations are now stored in theory and can be accessed via
  3360 <function_name>.simps.
  3361 
  3362 INCOMPATIBILITIES:
  3363 
  3364   - Theories using datatypes must now have theory Datatype as an
  3365     ancestor.
  3366   - The specific <typename>.induct_tac no longer exists - use the
  3367     generic induct_tac instead.
  3368   - natE has been renamed to nat.exhaust - use exhaust_tac
  3369     instead of res_inst_tac ... natE. Note that the variable
  3370     names in nat.exhaust differ from the names in natE, this
  3371     may cause some "fragile" proofs to fail.
  3372   - The theorems split_<typename>_case and split_<typename>_case_asm
  3373     have been renamed to <typename>.split and <typename>.split_asm.
  3374   - Since default sorts of type variables are now handled correctly,
  3375     some datatype definitions may have to be annotated with explicit
  3376     sort constraints.
  3377   - Primrec definitions no longer require function name and type
  3378     of recursive argument.
  3379 
  3380 Consider using isatool fixdatatype to adapt your theories and proof
  3381 scripts to the new package (backup your sources first!).
  3382 
  3383 
  3384 * HOL/record package: considerably improved implementation; now
  3385 includes concrete syntax for record types, terms, updates; theorems
  3386 for surjective pairing and splitting !!-bound record variables; proof
  3387 support is as follows:
  3388 
  3389   1) standard conversions (selectors or updates applied to record
  3390 constructor terms) are part of the standard simpset;
  3391 
  3392   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  3393 made part of standard simpset and claset via addIffs;
  3394 
  3395   3) a tactic for record field splitting (record_split_tac) is part of
  3396 the standard claset (addSWrapper);
  3397 
  3398 To get a better idea about these rules you may retrieve them via
  3399 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  3400 the name of your record type.
  3401 
  3402 The split tactic 3) conceptually simplifies by the following rule:
  3403 
  3404   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  3405 
  3406 Thus any record variable that is bound by meta-all will automatically
  3407 blow up into some record constructor term, consequently the
  3408 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  3409 solve record problems automatically.
  3410 
  3411 
  3412 * reorganized the main HOL image: HOL/Integ and String loaded by
  3413 default; theory Main includes everything;
  3414 
  3415 * automatic simplification of integer sums and comparisons, using cancellation;
  3416 
  3417 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  3418 
  3419 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  3420 
  3421 * many new identities for unions, intersections, set difference, etc.;
  3422 
  3423 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  3424 called split_if, split_split, split_sum_case and split_nat_case (to go
  3425 with add/delsplits);
  3426 
  3427 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  3428 (?x::unit) = (); this is made part of the default simpset, which COULD
  3429 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  3430 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  3431 unit_abs_eta_conv is added in order to counter the effect of
  3432 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  3433 %u.f();
  3434 
  3435 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  3436 makes more sense);
  3437 
  3438 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3439   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3440   disjointness reasoning but breaking a few old proofs.
  3441 
  3442 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  3443 to 'converse' from 'inverse' (for compatibility with ZF and some
  3444 literature);
  3445 
  3446 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  3447 the well-founded relation;
  3448 
  3449 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  3450     Compl A.  The "Compl" syntax remains available as input syntax for this
  3451     release ONLY.
  3452 
  3453 * HOL/Update: new theory of function updates:
  3454     f(a:=b) == %x. if x=a then b else f x
  3455 may also be iterated as in f(a:=b,c:=d,...);
  3456 
  3457 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  3458 
  3459 * HOL/List:
  3460   - new function list_update written xs[i:=v] that updates the i-th
  3461     list position. May also be iterated as in xs[i:=a,j:=b,...].
  3462   - new function `upt' written [i..j(] which generates the list
  3463     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  3464     bound write [i..j], which is a shorthand for [i..j+1(].
  3465   - new lexicographic orderings and corresponding wellfoundedness theorems.
  3466 
  3467 * HOL/Arith:
  3468   - removed 'pred' (predecessor) function;
  3469   - generalized some theorems about n-1;
  3470   - many new laws about "div" and "mod";
  3471   - new laws about greatest common divisors (see theory ex/Primes);
  3472 
  3473 * HOL/Relation: renamed the relational operator r^-1 "converse"
  3474 instead of "inverse";
  3475 
  3476 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  3477   of the multiset ordering;
  3478 
  3479 * directory HOL/Real: a construction of the reals using Dedekind cuts
  3480   (not included by default);
  3481 
  3482 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  3483 
  3484 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  3485   programs, i.e. different program variables may have different types.
  3486 
  3487 * calling (stac rew i) now fails if "rew" has no effect on the goal
  3488   [previously, this check worked only if the rewrite rule was unconditional]
  3489   Now rew can involve either definitions or equalities (either == or =).
  3490 
  3491 
  3492 *** ZF ***
  3493 
  3494 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  3495   only the theorems proved on ZF.ML;
  3496 
  3497 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3498   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3499   disjointness reasoning but breaking a few old proofs.
  3500 
  3501 * ZF/Update: new theory of function updates
  3502     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  3503   may also be iterated as in f(a:=b,c:=d,...);
  3504 
  3505 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  3506 
  3507 * calling (stac rew i) now fails if "rew" has no effect on the goal
  3508   [previously, this check worked only if the rewrite rule was unconditional]
  3509   Now rew can involve either definitions or equalities (either == or =).
  3510 
  3511 * case_tac provided for compatibility with HOL
  3512     (like the old excluded_middle_tac, but with subgoals swapped)
  3513 
  3514 
  3515 *** Internal programming interfaces ***
  3516 
  3517 * Pure: several new basic modules made available for general use, see
  3518 also src/Pure/README;
  3519 
  3520 * improved the theory data mechanism to support encapsulation (data
  3521 kind name replaced by private Object.kind, acting as authorization
  3522 key); new type-safe user interface via functor TheoryDataFun; generic
  3523 print_data function becomes basically useless;
  3524 
  3525 * removed global_names compatibility flag -- all theory declarations
  3526 are qualified by default;
  3527 
  3528 * module Pure/Syntax now offers quote / antiquote translation
  3529 functions (useful for Hoare logic etc. with implicit dependencies);
  3530 see HOL/ex/Antiquote for an example use;
  3531 
  3532 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  3533 cterm -> thm;
  3534 
  3535 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  3536 subgoal;
  3537 
  3538 * Display.print_goals function moved to Locale.print_goals;
  3539 
  3540 * standard print function for goals supports current_goals_markers
  3541 variable for marking begin of proof, end of proof, start of goal; the
  3542 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  3543 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  3544 for example;
  3545 
  3546 
  3547 
  3548 New in Isabelle98 (January 1998)
  3549 --------------------------------
  3550 
  3551 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3552 
  3553 * changed lexical syntax of terms / types: dots made part of long
  3554 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  3555 
  3556 * simpset (and claset) reference variable replaced by functions
  3557 simpset / simpset_ref;
  3558 
  3559 * no longer supports theory aliases (via merge) and non-trivial
  3560 implicit merge of thms' signatures;
  3561 
  3562 * most internal names of constants changed due to qualified names;
  3563 
  3564 * changed Pure/Sequence interface (see Pure/seq.ML);
  3565 
  3566 
  3567 *** General Changes ***
  3568 
  3569 * hierachically structured name spaces (for consts, types, axms, thms
  3570 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  3571 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  3572 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  3573 long_names for fully qualified output names; NOTE: ML programs
  3574 (special tactics, packages etc.) referring to internal names may have
  3575 to be adapted to cope with fully qualified names; in case of severe
  3576 backward campatibility problems try setting 'global_names' at compile
  3577 time to have enrything declared within a flat name space; one may also
  3578 fine tune name declarations in theories via the 'global' and 'local'
  3579 section;
  3580 
  3581 * reimplemented the implicit simpset and claset using the new anytype
  3582 data filed in signatures; references simpset:simpset ref etc. are
  3583 replaced by functions simpset:unit->simpset and
  3584 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  3585 to patch your ML files accordingly;
  3586 
  3587 * HTML output now includes theory graph data for display with Java
  3588 applet or isatool browser; data generated automatically via isatool
  3589 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  3590 
  3591 * defs may now be conditional; improved rewrite_goals_tac to handle
  3592 conditional equations;
  3593 
  3594 * defs now admits additional type arguments, using TYPE('a) syntax;
  3595 
  3596 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  3597 creates a new theory node; implicit merge of thms' signatures is
  3598 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  3599 transfer:theory->thm->thm in (rare) cases;
  3600 
  3601 * improved handling of draft signatures / theories; draft thms (and
  3602 ctyps, cterms) are automatically promoted to real ones;
  3603 
  3604 * slightly changed interfaces for oracles: admit many per theory, named
  3605 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  3606 
  3607 * print_goals: optional output of const types (set show_consts and
  3608 show_types);
  3609 
  3610 * improved output of warnings (###) and errors (***);
  3611 
  3612 * subgoal_tac displays a warning if the new subgoal has type variables;
  3613 
  3614 * removed old README and Makefiles;
  3615 
  3616 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  3617 
  3618 * removed obsolete init_pps and init_database;
  3619 
  3620 * deleted the obsolete tactical STATE, which was declared by
  3621     fun STATE tacfun st = tacfun st st;
  3622 
  3623 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  3624 (which abbreviates $HOME);
  3625 
  3626 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  3627 use isatool fixseq to adapt your ML programs (this works for fully
  3628 qualified references to the Sequence structure only!);
  3629 
  3630 * use_thy no longer requires writable current directory; it always
  3631 reloads .ML *and* .thy file, if either one is out of date;
  3632 
  3633 
  3634 *** Classical Reasoner ***
  3635 
  3636 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  3637 tactics that use classical reasoning to simplify a subgoal without
  3638 splitting it into several subgoals;
  3639 
  3640 * Safe_tac: like safe_tac but uses the default claset;
  3641 
  3642 
  3643 *** Simplifier ***
  3644 
  3645 * added simplification meta rules:
  3646     (asm_)(full_)simplify: simpset -> thm -> thm;
  3647 
  3648 * simplifier.ML no longer part of Pure -- has to be loaded by object
  3649 logics (again);
  3650 
  3651 * added prems argument to simplification procedures;
  3652 
  3653 * HOL, FOL, ZF: added infix function `addsplits':
  3654   instead of `<simpset> setloop (split_tac <thms>)'
  3655   you can simply write `<simpset> addsplits <thms>'
  3656 
  3657 
  3658 *** Syntax ***
  3659 
  3660 * TYPE('a) syntax for type reflection terms;
  3661 
  3662 * no longer handles consts with name "" -- declare as 'syntax' instead;
  3663 
  3664 * pretty printer: changed order of mixfix annotation preference (again!);
  3665 
  3666 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  3667 
  3668 
  3669 *** HOL ***
  3670 
  3671 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3672   with `addloop' of the simplifier to faciliate case splitting in premises.
  3673 
  3674 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  3675 
  3676 * HOL/Auth: new protocol proofs including some for the Internet
  3677   protocol TLS;
  3678 
  3679 * HOL/Map: new theory of `maps' a la VDM;
  3680 
  3681 * HOL/simplifier: simplification procedures nat_cancel_sums for
  3682 cancelling out common nat summands from =, <, <= (in)equalities, or
  3683 differences; simplification procedures nat_cancel_factor for
  3684 cancelling common factor from =, <, <= (in)equalities over natural
  3685 sums; nat_cancel contains both kinds of procedures, it is installed by
  3686 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  3687 
  3688 * HOL/simplifier: terms of the form
  3689   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  3690   are rewritten to
  3691   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  3692   and those of the form
  3693   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  3694   are rewritten to
  3695   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  3696 
  3697 * HOL/datatype
  3698   Each datatype `t' now comes with a theorem `split_t_case' of the form
  3699 
  3700   P(t_case f1 ... fn x) =
  3701      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  3702         ...
  3703        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  3704      )
  3705 
  3706   and a theorem `split_t_case_asm' of the form
  3707 
  3708   P(t_case f1 ... fn x) =
  3709     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  3710         ...
  3711        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  3712      )
  3713   which can be added to a simpset via `addsplits'. The existing theorems
  3714   expand_list_case and expand_option_case have been renamed to
  3715   split_list_case and split_option_case.
  3716 
  3717 * HOL/Arithmetic:
  3718   - `pred n' is automatically converted to `n-1'.
  3719     Users are strongly encouraged not to use `pred' any longer,
  3720     because it will disappear altogether at some point.
  3721   - Users are strongly encouraged to write "0 < n" rather than
  3722     "n ~= 0". Theorems and proof tools have been modified towards this
  3723     `standard'.
  3724 
  3725 * HOL/Lists:
  3726   the function "set_of_list" has been renamed "set" (and its theorems too);
  3727   the function "nth" now takes its arguments in the reverse order and
  3728   has acquired the infix notation "!" as in "xs!n".
  3729 
  3730 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  3731 
  3732 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  3733   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  3734 
  3735 * HOL/record: extensible records with schematic structural subtyping
  3736 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  3737 still lacks various theorems and concrete record syntax;
  3738 
  3739 
  3740 *** HOLCF ***
  3741 
  3742 * removed "axioms" and "generated by" sections;
  3743 
  3744 * replaced "ops" section by extended "consts" section, which is capable of
  3745   handling the continuous function space "->" directly;
  3746 
  3747 * domain package:
  3748   . proves theorems immediately and stores them in the theory,
  3749   . creates hierachical name space,
  3750   . now uses normal mixfix annotations (instead of cinfix...),
  3751   . minor changes to some names and values (for consistency),
  3752   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  3753   . separator between mutual domain defs: changed "," to "and",
  3754   . improved handling of sort constraints;  now they have to
  3755     appear on the left-hand side of the equations only;
  3756 
  3757 * fixed LAM <x,y,zs>.b syntax;
  3758 
  3759 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  3760 adm (%x. P (t x)), where P is chainfinite and t continuous;
  3761 
  3762 
  3763 *** FOL and ZF ***
  3764 
  3765 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3766   with `addloop' of the simplifier to faciliate case splitting in premises.
  3767 
  3768 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  3769 in HOL, they strip ALL and --> from proved theorems;
  3770 
  3771 
  3772 
  3773 New in Isabelle94-8 (May 1997)
  3774 ------------------------------
  3775 
  3776 *** General Changes ***
  3777 
  3778 * new utilities to build / run / maintain Isabelle etc. (in parts
  3779 still somewhat experimental); old Makefiles etc. still functional;
  3780 
  3781 * new 'Isabelle System Manual';
  3782 
  3783 * INSTALL text, together with ./configure and ./build scripts;
  3784 
  3785 * reimplemented type inference for greater efficiency, better error
  3786 messages and clean internal interface;
  3787 
  3788 * prlim command for dealing with lots of subgoals (an easier way of
  3789 setting goals_limit);
  3790 
  3791 
  3792 *** Syntax ***
  3793 
  3794 * supports alternative (named) syntax tables (parser and pretty
  3795 printer); internal interface is provided by add_modesyntax(_i);
  3796 
  3797 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  3798 be used in conjunction with the Isabelle symbol font; uses the
  3799 "symbols" syntax table;
  3800 
  3801 * added token_translation interface (may translate name tokens in
  3802 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  3803 the current print_mode); IMPORTANT: user print translation functions
  3804 are responsible for marking newly introduced bounds
  3805 (Syntax.mark_boundT);
  3806 
  3807 * token translations for modes "xterm" and "xterm_color" that display
  3808 names in bold, underline etc. or colors (which requires a color
  3809 version of xterm);
  3810 
  3811 * infixes may now be declared with names independent of their syntax;
  3812 
  3813 * added typed_print_translation (like print_translation, but may
  3814 access type of constant);
  3815 
  3816 
  3817 *** Classical Reasoner ***
  3818 
  3819 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  3820 some limitations.  Blast_tac...
  3821   + ignores addss, addbefore, addafter; this restriction is intrinsic
  3822   + ignores elimination rules that don't have the correct format
  3823         (the conclusion MUST be a formula variable)
  3824   + ignores types, which can make HOL proofs fail
  3825   + rules must not require higher-order unification, e.g. apply_type in ZF
  3826     [message "Function Var's argument not a bound variable" relates to this]
  3827   + its proof strategy is more general but can actually be slower
  3828 
  3829 * substitution with equality assumptions no longer permutes other
  3830 assumptions;
  3831 
  3832 * minor changes in semantics of addafter (now called addaltern); renamed
  3833 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  3834 (and access functions for it);
  3835 
  3836 * improved combination of classical reasoner and simplifier:
  3837   + functions for handling clasimpsets
  3838   + improvement of addss: now the simplifier is called _after_ the
  3839     safe steps.
  3840   + safe variant of addss called addSss: uses safe simplifications
  3841     _during_ the safe steps. It is more complete as it allows multiple
  3842     instantiations of unknowns (e.g. with slow_tac).
  3843 
  3844 *** Simplifier ***
  3845 
  3846 * added interface for simplification procedures (functions that
  3847 produce *proven* rewrite rules on the fly, depending on current
  3848 redex);
  3849 
  3850 * ordering on terms as parameter (used for ordered rewriting);
  3851 
  3852 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  3853 
  3854 * the solver is now split into a safe and an unsafe part.
  3855 This should be invisible for the normal user, except that the
  3856 functions setsolver and addsolver have been renamed to setSolver and
  3857 addSolver; added safe_asm_full_simp_tac;
  3858 
  3859 
  3860 *** HOL ***
  3861 
  3862 * a generic induction tactic `induct_tac' which works for all datatypes and
  3863 also for type `nat';
  3864 
  3865 * a generic case distinction tactic `exhaust_tac' which works for all
  3866 datatypes and also for type `nat';
  3867 
  3868 * each datatype comes with a function `size';
  3869 
  3870 * patterns in case expressions allow tuple patterns as arguments to
  3871 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  3872 
  3873 * primrec now also works with type nat;
  3874 
  3875 * recdef: a new declaration form, allows general recursive functions to be
  3876 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  3877 
  3878 * the constant for negation has been renamed from "not" to "Not" to
  3879 harmonize with FOL, ZF, LK, etc.;
  3880 
  3881 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  3882 infinite lists;
  3883 
  3884 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  3885 
  3886 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  3887 problems in commutative rings, using axiomatic type classes for + and *;
  3888 
  3889 * more examples in HOL/MiniML and HOL/Auth;
  3890 
  3891 * more default rewrite rules for quantifiers, union/intersection;
  3892 
  3893 * a new constant `arbitrary == @x.False';
  3894 
  3895 * HOLCF/IOA replaces old HOL/IOA;
  3896 
  3897 * HOLCF changes: derived all rules and arities
  3898   + axiomatic type classes instead of classes
  3899   + typedef instead of faking type definitions
  3900   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  3901   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  3902   + eliminated the types void, one, tr
  3903   + use unit lift and bool lift (with translations) instead of one and tr
  3904   + eliminated blift from Lift3.thy (use Def instead of blift)
  3905   all eliminated rules are derived as theorems --> no visible changes ;
  3906 
  3907 
  3908 *** ZF ***
  3909 
  3910 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  3911 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  3912 as ZF_cs addSIs [equalityI];
  3913 
  3914 
  3915 
  3916 New in Isabelle94-7 (November 96)
  3917 ---------------------------------
  3918 
  3919 * allowing negative levels (as offsets) in prlev and choplev;
  3920 
  3921 * super-linear speedup for large simplifications;
  3922 
  3923 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  3924 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  3925 FAIL); can suppress it using the command Delsimps (ex_simps @
  3926 all_simps); De Morgan laws are also now included, by default;
  3927 
  3928 * improved printing of ==>  :  ~:
  3929 
  3930 * new object-logic "Sequents" adds linear logic, while replacing LK
  3931 and Modal (thanks to Sara Kalvala);
  3932 
  3933 * HOL/Auth: correctness proofs for authentication protocols;
  3934 
  3935 * HOL: new auto_tac combines rewriting and classical reasoning (many
  3936 examples on HOL/Auth);
  3937 
  3938 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  3939 the rewriter and classical reasoner simultaneously;
  3940 
  3941 * function uresult no longer returns theorems in "standard" format;
  3942 regain previous version by: val uresult = standard o uresult;
  3943 
  3944 
  3945 
  3946 New in Isabelle94-6
  3947 -------------------
  3948 
  3949 * oracles -- these establish an interface between Isabelle and trusted
  3950 external reasoners, which may deliver results as theorems;
  3951 
  3952 * proof objects (in particular record all uses of oracles);
  3953 
  3954 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  3955 
  3956 * "constdefs" section in theory files;
  3957 
  3958 * "primrec" section (HOL) no longer requires names;
  3959 
  3960 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  3961 
  3962 
  3963 
  3964 New in Isabelle94-5
  3965 -------------------
  3966 
  3967 * reduced space requirements;
  3968 
  3969 * automatic HTML generation from theories;
  3970 
  3971 * theory files no longer require "..." (quotes) around most types;
  3972 
  3973 * new examples, including two proofs of the Church-Rosser theorem;
  3974 
  3975 * non-curried (1994) version of HOL is no longer distributed;
  3976 
  3977 
  3978 
  3979 New in Isabelle94-4
  3980 -------------------
  3981 
  3982 * greatly reduced space requirements;
  3983 
  3984 * theory files (.thy) no longer require \...\ escapes at line breaks;
  3985 
  3986 * searchable theorem database (see the section "Retrieving theorems" on
  3987 page 8 of the Reference Manual);
  3988 
  3989 * new examples, including Grabczewski's monumental case study of the
  3990 Axiom of Choice;
  3991 
  3992 * The previous version of HOL renamed to Old_HOL;
  3993 
  3994 * The new version of HOL (previously called CHOL) uses a curried syntax
  3995 for functions.  Application looks like f a b instead of f(a,b);
  3996 
  3997 * Mutually recursive inductive definitions finally work in HOL;
  3998 
  3999 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4000 translates to the operator "split";
  4001 
  4002 
  4003 
  4004 New in Isabelle94-3
  4005 -------------------
  4006 
  4007 * new infix operator, addss, allowing the classical reasoner to
  4008 perform simplification at each step of its search.  Example:
  4009         fast_tac (cs addss ss)
  4010 
  4011 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4012 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4013 look like (a,b) instead of <a,b>;
  4014 
  4015 * PLEASE NOTE: CHOL will eventually replace HOL!
  4016 
  4017 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4018 It translates to the operator "split".  A new theory of integers is available;
  4019 
  4020 * In ZF, integer numerals now denote two's-complement binary integers.
  4021 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4022 
  4023 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4024 of the Axiom of Choice;
  4025 
  4026 
  4027 
  4028 New in Isabelle94-2
  4029 -------------------
  4030 
  4031 * Significantly faster resolution;
  4032 
  4033 * the different sections in a .thy file can now be mixed and repeated
  4034 freely;
  4035 
  4036 * Database of theorems for FOL, HOL and ZF.  New
  4037 commands including qed, qed_goal and bind_thm store theorems in the database.
  4038 
  4039 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4040 a given theory (thms_of), or find out what theory a theorem was proved in
  4041 (theory_of_thm);
  4042 
  4043 * Bugs fixed in the inductive definition and datatype packages;
  4044 
  4045 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4046 and HOL_dup_cs obsolete;
  4047 
  4048 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  4049 have been removed;
  4050 
  4051 * Simpler definition of function space in ZF;
  4052 
  4053 * new results about cardinal and ordinal arithmetic in ZF;
  4054 
  4055 * 'subtype' facility in HOL for introducing new types as subsets of existing
  4056 types;
  4057 
  4058 
  4059 $Id$