NEWS
author webertj
Fri Sep 23 23:28:59 2005 +0200 (2005-09-23)
changeset 17619 026f7bbc8a0f
parent 17597 dac8dd2272cd
child 17641 5ec55c1fa116
permissions -rw-r--r--
new sat tactic
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2005 (September 2005)
     5 ------------------------------------
     6 
     7 *** General ***
     8 
     9 * Theory headers: the new header syntax for Isar theories is
    10 
    11   theory <name>
    12   imports <theory1> ... <theoryN>
    13   uses <file1> ... <fileM>
    14   begin
    15 
    16 where the 'uses' part is optional.  The previous syntax
    17 
    18   theory <name> = <theory1> + ... + <theoryN>:
    19 
    20 will disappear in the next release.  Use isatool fixheaders to convert
    21 existing theory files.  Note that there is no change in ancient
    22 non-Isar theories now, but these will disappear soon.
    23 
    24 * Theory loader: parent theories can now also be referred to via
    25 relative and absolute paths.
    26 
    27 * Command 'find_theorems' searches for a list of criteria instead of a
    28 list of constants. Known criteria are: intro, elim, dest, name:string,
    29 simp:term, and any term. Criteria can be preceded by '-' to select
    30 theorems that do not match. Intro, elim, dest select theorems that
    31 match the current goal, name:s selects theorems whose fully qualified
    32 name contain s, and simp:term selects all simplification rules whose
    33 lhs match term.  Any other term is interpreted as pattern and selects
    34 all theorems matching the pattern. Available in ProofGeneral under
    35 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
    36 
    37   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
    38 
    39 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
    40 matching the current goal as introduction rule and not having "HOL."
    41 in their name (i.e. not being defined in theory HOL).
    42 
    43 * Command 'thms_containing' has been discontinued in favour of
    44 'find_theorems'; INCOMPATIBILITY.
    45 
    46 * Communication with Proof General is now 8bit clean, which means that
    47 Unicode text in UTF-8 encoding may be used within theory texts (both
    48 formal and informal parts).  Cf. option -U of the Isabelle Proof
    49 General interface.  Here are some simple examples (cf. src/HOL/ex):
    50 
    51   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
    52   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
    53 
    54 * Improved efficiency of the Simplifier and, to a lesser degree, the
    55 Classical Reasoner.  Typical big applications run around 2 times
    56 faster.
    57 
    58 * ProofGeneral interface: the default settings no longer prefer xemacs
    59 over GNU emacs.  Users typically need to experiment with various
    60 variations on PROOFGENERAL_OPTIONS="... -p emacs" to find the most
    61 stable Emacs version on their platform.
    62 
    63 
    64 *** Document preparation ***
    65 
    66 * Commands 'display_drafts' and 'print_drafts' perform simple output
    67 of raw sources.  Only those symbols that do not require additional
    68 LaTeX packages (depending on comments in isabellesym.sty) are
    69 displayed properly, everything else is left verbatim.  isatool display
    70 and isatool print are used as front ends (these are subject to the
    71 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
    72 
    73 * Command tags control specific markup of certain regions of text,
    74 notably folding and hiding.  Predefined tags include "theory" (for
    75 theory begin and end), "proof" for proof commands, and "ML" for
    76 commands involving ML code; the additional tags "visible" and
    77 "invisible" are unused by default.  Users may give explicit tag
    78 specifications in the text, e.g. ''by %invisible (auto)''.  The
    79 interpretation of tags is determined by the LaTeX job during document
    80 preparation: see option -V of isatool usedir, or options -n and -t of
    81 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
    82 \isadroptag.
    83 
    84 Several document versions may be produced at the same time via isatool
    85 usedir (the generated index.html will link all of them).  Typical
    86 specifications include ''-V document=theory,proof,ML'' to present
    87 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
    88 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
    89 these parts without any formal replacement text.  The Isabelle site
    90 default settings produce ''document'' and ''outline'' versions as
    91 specified above.
    92 
    93 * Several new antiquotations:
    94 
    95   @{term_type term} prints a term with its type annotated;
    96 
    97   @{typeof term} prints the type of a term;
    98 
    99   @{const const} is the same as @{term const}, but checks that the
   100   argument is a known logical constant;
   101 
   102   @{term_style style term} and @{thm_style style thm} print a term or
   103   theorem applying a "style" to it
   104 
   105   @{ML text}
   106 
   107 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
   108 definitions, equations, inequations etc., 'concl' printing only the
   109 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
   110 to print the specified premise.  TermStyle.add_style provides an ML
   111 interface for introducing further styles.  See also the "LaTeX Sugar"
   112 document practical applications.  The ML antiquotation prints
   113 type-checked ML expressions verbatim.
   114 
   115 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
   116 and 'text' support optional locale specification '(in loc)', which
   117 specifies the default context for interpreting antiquotations.  For
   118 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
   119 
   120 * Option 'locale=NAME' of antiquotations specifies an alternative
   121 context interpreting the subsequent argument.  For example: @{thm
   122 [locale=lattice] inf_assoc}.
   123 
   124 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
   125 a proof context.
   126 
   127 * Proper output of antiquotations for theory commands involving a
   128 proof context (such as 'locale' or 'theorem (in loc) ...').
   129 
   130 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
   131 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
   132 
   133 * isatool usedir: new option -C (default true) controls whether option
   134 -D should include a copy of the original document directory; -C false
   135 prevents unwanted effects such as copying of administrative CVS data.
   136 
   137 
   138 *** Pure ***
   139 
   140 * Considerably improved version of 'constdefs' command.  Now performs
   141 automatic type-inference of declared constants; additional support for
   142 local structure declarations (cf. locales and HOL records), see also
   143 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
   144 sequential dependencies of definitions within a single 'constdefs'
   145 section; moreover, the declared name needs to be an identifier.  If
   146 all fails, consider to fall back on 'consts' and 'defs' separately.
   147 
   148 * Improved indexed syntax and implicit structures.  First of all,
   149 indexed syntax provides a notational device for subscripted
   150 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
   151 expressions.  Secondly, in a local context with structure
   152 declarations, number indexes \<^sub>n or the empty index (default
   153 number 1) refer to a certain fixed variable implicitly; option
   154 show_structs controls printing of implicit structures.  Typical
   155 applications of these concepts involve record types and locales.
   156 
   157 * New command 'no_syntax' removes grammar declarations (and
   158 translations) resulting from the given syntax specification, which is
   159 interpreted in the same manner as for the 'syntax' command.
   160 
   161 * 'Advanced' translation functions (parse_translation etc.) may depend
   162 on the signature of the theory context being presently used for
   163 parsing/printing, see also isar-ref manual.
   164 
   165 * Improved 'oracle' command provides a type-safe interface to turn an
   166 ML expression of type theory -> T -> term into a primitive rule of
   167 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
   168 is already included here); see also FOL/ex/IffExample.thy;
   169 INCOMPATIBILITY.
   170 
   171 * axclass: name space prefix for class "c" is now "c_class" (was "c"
   172 before); "cI" is no longer bound, use "c.intro" instead.
   173 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
   174 axclasses vs. locales.
   175 
   176 * Improved internal renaming of symbolic identifiers -- attach primes
   177 instead of base 26 numbers.
   178 
   179 * New flag show_question_marks controls printing of leading question
   180 marks in schematic variable names.
   181 
   182 * In schematic variable names, *any* symbol following \<^isub> or
   183 \<^isup> is now treated as part of the base name.  For example, the
   184 following works without printing of awkward ".0" indexes:
   185 
   186   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
   187     by simp
   188 
   189 * Inner syntax includes (*(*nested*) comments*).
   190 
   191 * Pretty printer now supports unbreakable blocks, specified in mixfix
   192 annotations as "(00...)".
   193 
   194 * Clear separation of logical types and nonterminals, where the latter
   195 may only occur in 'syntax' specifications or type abbreviations.
   196 Before that distinction was only partially implemented via type class
   197 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
   198 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
   199 exotic syntax specifications may require further adaption
   200 (e.g. Cube/Base.thy).
   201 
   202 * Removed obsolete type class "logic", use the top sort {} instead.
   203 Note that non-logical types should be declared as 'nonterminals'
   204 rather than 'types'.  INCOMPATIBILITY for new object-logic
   205 specifications.
   206 
   207 * 'defs': more well-formedness checks of overloaded definitions.
   208 
   209 * Attributes 'induct' and 'cases': type or set names may now be
   210 locally fixed variables as well.
   211 
   212 * Simplifier: can now control the depth to which conditional rewriting
   213 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
   214 Limit.
   215 
   216 * Simplifier: simplification procedures may now take the current
   217 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
   218 interface), which is very useful for calling the Simplifier
   219 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
   220 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
   221 low-level mk_simproc no longer applies Logic.varify internally, to
   222 allow for use in a context of fixed variables.
   223 
   224 * thin_tac now works even if the assumption being deleted contains !!
   225 or ==>.  More generally, erule now works even if the major premise of
   226 the elimination rule contains !! or ==>.
   227 
   228 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
   229 
   230 * Reorganized bootstrapping of the Pure theories; CPure is now derived
   231 from Pure, which contains all common declarations already.  Both
   232 theories are defined via plain Isabelle/Isar .thy files.
   233 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
   234 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
   235 use isatool fixcpure to adapt your theory and ML sources.
   236 
   237 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
   238 selections of theorems in named facts via index ranges.
   239 
   240 * 'print_theorems': in theory mode, really print the difference
   241 wrt. the last state (works for interactive theory development only),
   242 in proof mode print all local facts (cf. 'print_facts');
   243 
   244 * 'hide': option '(open)' hides only base names.
   245 
   246 * More efficient treatment of intermediate checkpoints in interactive
   247 theory development.
   248 
   249 
   250 *** Locales ***
   251 
   252 * New commands for the interpretation of locale expressions in
   253 theories (1), locales (2) and proof contexts (3).  These generate
   254 proof obligations from the expression specification.  After the
   255 obligations have been discharged, theorems of the expression are added
   256 to the theory, target locale or proof context.  The synopsis of the
   257 commands is a follows:
   258 
   259   (1) interpretation expr inst
   260   (2) interpretation target < expr
   261   (3) interpret expr inst
   262 
   263 Interpretation in theories and proof contexts require a parameter
   264 instantiation of terms from the current context.  This is applied to
   265 specifications and theorems of the interpreted expression.
   266 Interpretation in locales only permits parameter renaming through the
   267 locale expression.  Interpretation is smart in that interpretations
   268 that are active already do not occur in proof obligations, neither are
   269 instantiated theorems stored in duplicate.  Use 'print_interps' to
   270 inspect active interpretations of a particular locale.  For details,
   271 see the Isar Reference manual.  Examples can be found in
   272 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
   273 
   274 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
   275 'interpret' instead.
   276 
   277 * New context element 'constrains' for adding type constraints to
   278 parameters.
   279 
   280 * Context expressions: renaming of parameters with syntax
   281 redeclaration.
   282 
   283 * Locale declaration: 'includes' disallowed.
   284 
   285 * Proper static binding of attribute syntax -- i.e. types / terms /
   286 facts mentioned as arguments are always those of the locale definition
   287 context, independently of the context of later invocations.  Moreover,
   288 locale operations (renaming and type / term instantiation) are applied
   289 to attribute arguments as expected.
   290 
   291 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
   292 actual attributes; rare situations may require Attrib.attribute to
   293 embed those attributes into Attrib.src that lack concrete syntax.
   294 Attribute implementations need to cooperate properly with the static
   295 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
   296 Attrib.XXX_thm etc. already do the right thing without further
   297 intervention.  Only unusual applications -- such as "where" or "of"
   298 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
   299 on the context and the facts involved -- may have to assign parsed
   300 values to argument tokens explicitly.
   301 
   302 * Changed parameter management in theorem generation for long goal
   303 statements with 'includes'.  INCOMPATIBILITY: produces a different
   304 theorem statement in rare situations.
   305 
   306 * Locale inspection command 'print_locale' omits notes elements.  Use
   307 'print_locale!' to have them included in the output.
   308 
   309 
   310 *** Provers ***
   311 
   312 * Provers/hypsubst.ML: improved version of the subst method, for
   313 single-step rewriting: it now works in bound variable contexts. New is
   314 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
   315 rewrite a different subterm than the original subst method, which is
   316 still available as 'simplesubst'.
   317 
   318 * Provers/quasi.ML: new transitivity reasoners for transitivity only
   319 and quasi orders.
   320 
   321 * Provers/trancl.ML: new transitivity reasoner for transitive and
   322 reflexive-transitive closure of relations.
   323 
   324 * Provers/blast.ML: new reference depth_limit to make blast's depth
   325 limit (previously hard-coded with a value of 20) user-definable.
   326 
   327 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
   328 is peformed already.  Object-logics merely need to finish their
   329 initial simpset configuration as before.  INCOMPATIBILITY.
   330 
   331 
   332 *** HOL ***
   333 
   334 * Symbolic syntax of Hilbert Choice Operator is now as follows:
   335 
   336   syntax (epsilon)
   337     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
   338 
   339 The symbol \<some> is displayed as the alternative epsilon of LaTeX
   340 and x-symbol; use option '-m epsilon' to get it actually printed.
   341 Moreover, the mathematically important symbolic identifier \<epsilon>
   342 becomes available as variable, constant etc.  INCOMPATIBILITY,
   343 
   344 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
   345 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
   346 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
   347 support corresponding Isar calculations.
   348 
   349 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
   350 instead of ":".
   351 
   352 * theory SetInterval: changed the syntax for open intervals:
   353 
   354   Old       New
   355   {..n(}    {..<n}
   356   {)n..}    {n<..}
   357   {m..n(}   {m..<n}
   358   {)m..n}   {m<..n}
   359   {)m..n(}  {m<..<n}
   360 
   361 The old syntax is still supported but will disappear in the next
   362 release.  For conversion use the following Emacs search and replace
   363 patterns (these are not perfect but work quite well):
   364 
   365   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
   366   \.\.\([^(}]*\)(}  ->  \.\.<\1}
   367 
   368 * Theory Commutative_Ring (in Library): method comm_ring for proving
   369 equalities in commutative rings; method 'algebra' provides a generic
   370 interface.
   371 
   372 * Theory Finite_Set: changed the syntax for 'setsum', summation over
   373 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
   374 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
   375 be a tuple pattern.
   376 
   377 Some new syntax forms are available:
   378 
   379   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
   380   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
   381   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
   382   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
   383 
   384 The latter form "\<Sum>x < k. e" used to be based on a separate
   385 function "Summation", which has been discontinued.
   386 
   387 * theory Finite_Set: in structured induction proofs, the insert case
   388 is now 'case (insert x F)' instead of the old counterintuitive 'case
   389 (insert F x)'.
   390 
   391 * The 'refute' command has been extended to support a much larger
   392 fragment of HOL, including axiomatic type classes, constdefs and
   393 typedefs, inductive datatypes and recursion.
   394 
   395 * New tactic 'sat' to prove propositional tautologies.  Requires
   396 zChaff with proof generation to be installed.
   397 
   398 * Datatype induction via method 'induct' now preserves the name of the
   399 induction variable. For example, when proving P(xs::'a list) by
   400 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
   401 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
   402 in unstructured proof scripts.
   403 
   404 * Reworked implementation of records.  Improved scalability for
   405 records with many fields, avoiding performance problems for type
   406 inference. Records are no longer composed of nested field types, but
   407 of nested extension types. Therefore the record type only grows linear
   408 in the number of extensions and not in the number of fields.  The
   409 top-level (users) view on records is preserved.  Potential
   410 INCOMPATIBILITY only in strange cases, where the theory depends on the
   411 old record representation. The type generated for a record is called
   412 <record_name>_ext_type.
   413 
   414 Flag record_quick_and_dirty_sensitive can be enabled to skip the
   415 proofs triggered by a record definition or a simproc (if
   416 quick_and_dirty is enabled).  Definitions of large records can take
   417 quite long.
   418 
   419 New simproc record_upd_simproc for simplification of multiple record
   420 updates enabled by default.  Moreover, trivial updates are also
   421 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
   422 occasionally, since simplification is more powerful by default.
   423 
   424 * typedef: proper support for polymorphic sets, which contain extra
   425 type-variables in the term.
   426 
   427 * Simplifier: automatically reasons about transitivity chains
   428 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
   429 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
   430 old proofs break occasionally as simplification may now solve more
   431 goals than previously.
   432 
   433 * Simplifier: converts x <= y into x = y if assumption y <= x is
   434 present.  Works for all partial orders (class "order"), in particular
   435 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
   436 just like y <= x.
   437 
   438 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
   439 bound variable or a constant then the let is unfolded.  Otherwise
   440 first a is simplified to b, and then f b is simplified to g. If
   441 possible we abstract b from g arriving at "let x = b in h x",
   442 otherwise we unfold the let and arrive at g.  The simproc can be
   443 enabled/disabled by the reference use_let_simproc.  Potential
   444 INCOMPATIBILITY since simplification is more powerful by default.
   445 
   446 * Classical reasoning: the meson method now accepts theorems as arguments.
   447 
   448 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
   449 jobs to provide advice on the provability of subgoals.
   450 
   451 * Theory OrderedGroup and Ring_and_Field: various additions and
   452 improvements to faciliate calculations involving equalities and
   453 inequalities.
   454 
   455 The following theorems have been eliminated or modified
   456 (INCOMPATIBILITY):
   457 
   458   abs_eq             now named abs_of_nonneg
   459   abs_of_ge_0        now named abs_of_nonneg
   460   abs_minus_eq       now named abs_of_nonpos
   461   imp_abs_id         now named abs_of_nonneg
   462   imp_abs_neg_id     now named abs_of_nonpos
   463   mult_pos           now named mult_pos_pos
   464   mult_pos_le        now named mult_nonneg_nonneg
   465   mult_pos_neg_le    now named mult_nonneg_nonpos
   466   mult_pos_neg2_le   now named mult_nonneg_nonpos2
   467   mult_neg           now named mult_neg_neg
   468   mult_neg_le        now named mult_nonpos_nonpos
   469 
   470 * Theory Parity: added rules for simplifying exponents.
   471 
   472 * Theory List:
   473 
   474 The following theorems have been eliminated or modified
   475 (INCOMPATIBILITY):
   476 
   477   list_all_Nil       now named list_all.simps(1)
   478   list_all_Cons      now named list_all.simps(2)
   479   list_all_conv      now named list_all_iff
   480   set_mem_eq         now named mem_iff
   481 
   482 * Theories SetsAndFunctions and BigO (see HOL/Library) support
   483 asymptotic "big O" calculations.  See the notes in BigO.thy.
   484 
   485 
   486 *** HOL-Complex ***
   487 
   488 * Theory RealDef: better support for embedding natural numbers and
   489 integers in the reals.
   490 
   491 The following theorems have been eliminated or modified
   492 (INCOMPATIBILITY):
   493 
   494   exp_ge_add_one_self  now requires no hypotheses
   495   real_of_int_add      reversed direction of equality (use [symmetric])
   496   real_of_int_minus    reversed direction of equality (use [symmetric])
   497   real_of_int_diff     reversed direction of equality (use [symmetric])
   498   real_of_int_mult     reversed direction of equality (use [symmetric])
   499 
   500 * Theory RComplete: expanded support for floor and ceiling functions.
   501 
   502 * Theory Ln is new, with properties of the natural logarithm
   503 
   504 * Hyperreal: There is a new type constructor "star" for making
   505 nonstandard types.  The old type names are now type synonyms:
   506 
   507   hypreal = real star
   508   hypnat = nat star
   509   hcomplex = complex star
   510 
   511 * Hyperreal: Many groups of similarly-defined constants have been
   512 replaced by polymorphic versions (INCOMPATIBILITY):
   513 
   514   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
   515 
   516   starset      <-- starsetNat, starsetC
   517   *s*          <-- *sNat*, *sc*
   518   starset_n    <-- starsetNat_n, starsetC_n
   519   *sn*         <-- *sNatn*, *scn*
   520   InternalSets <-- InternalNatSets, InternalCSets
   521 
   522   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
   523   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
   524   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
   525   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
   526   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
   527 
   528 * Hyperreal: Many type-specific theorems have been removed in favor of
   529 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
   530 
   531   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
   532   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
   533   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
   534   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
   535   right_minus <-- hypreal_add_minus
   536   left_minus <-- {hypreal,hcomplex}_add_minus_left
   537   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
   538   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
   539   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
   540   mult_1_right <-- hcomplex_mult_one_right
   541   mult_zero_left <-- hcomplex_mult_zero_left
   542   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
   543   right_distrib <-- hypnat_add_mult_distrib2
   544   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
   545   right_inverse <-- hypreal_mult_inverse
   546   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
   547   order_refl <-- {hypreal,hypnat}_le_refl
   548   order_trans <-- {hypreal,hypnat}_le_trans
   549   order_antisym <-- {hypreal,hypnat}_le_anti_sym
   550   order_less_le <-- {hypreal,hypnat}_less_le
   551   linorder_linear <-- {hypreal,hypnat}_le_linear
   552   add_left_mono <-- {hypreal,hypnat}_add_left_mono
   553   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
   554   add_nonneg_nonneg <-- hypreal_le_add_order
   555 
   556 * Hyperreal: Separate theorems having to do with type-specific
   557 versions of constants have been merged into theorems that apply to the
   558 new polymorphic constants (INCOMPATIBILITY):
   559 
   560   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
   561   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
   562   STAR_Un <-- {STAR,NatStar,STARC}_Un
   563   STAR_Int <-- {STAR,NatStar,STARC}_Int
   564   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
   565   STAR_subset <-- {STAR,NatStar,STARC}_subset
   566   STAR_mem <-- {STAR,NatStar,STARC}_mem
   567   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
   568   STAR_diff <-- {STAR,STARC}_diff
   569   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
   570     STARC_hcomplex_of_complex}_image_subset
   571   starset_n_Un <-- starset{Nat,C}_n_Un
   572   starset_n_Int <-- starset{Nat,C}_n_Int
   573   starset_n_Compl <-- starset{Nat,C}_n_Compl
   574   starset_n_diff <-- starset{Nat,C}_n_diff
   575   InternalSets_Un <-- Internal{Nat,C}Sets_Un
   576   InternalSets_Int <-- Internal{Nat,C}Sets_Int
   577   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
   578   InternalSets_diff <-- Internal{Nat,C}Sets_diff
   579   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
   580   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
   581   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
   582   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
   583   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
   584   starfun <-- starfun{Nat,Nat2,C,RC,CR}
   585   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
   586   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
   587   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
   588   starfun_diff <-- starfun{C,RC,CR}_diff
   589   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
   590   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
   591   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
   592   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
   593   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
   594   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
   595   starfun_Id <-- starfunC_Id
   596   starfun_approx <-- starfun{Nat,CR}_approx
   597   starfun_capprox <-- starfun{C,RC}_capprox
   598   starfun_abs <-- starfunNat_rabs
   599   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
   600   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
   601   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
   602   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
   603   starfun_add_capprox <-- starfun{C,RC}_add_capprox
   604   starfun_add_approx <-- starfunCR_add_approx
   605   starfun_inverse_inverse <-- starfunC_inverse_inverse
   606   starfun_divide <-- starfun{C,CR,RC}_divide
   607   starfun_n <-- starfun{Nat,C}_n
   608   starfun_n_mult <-- starfun{Nat,C}_n_mult
   609   starfun_n_add <-- starfun{Nat,C}_n_add
   610   starfun_n_add_minus <-- starfunNat_n_add_minus
   611   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
   612   starfun_n_minus <-- starfun{Nat,C}_n_minus
   613   starfun_n_eq <-- starfun{Nat,C}_n_eq
   614 
   615   star_n_add <-- {hypreal,hypnat,hcomplex}_add
   616   star_n_minus <-- {hypreal,hcomplex}_minus
   617   star_n_diff <-- {hypreal,hcomplex}_diff
   618   star_n_mult <-- {hypreal,hcomplex}_mult
   619   star_n_inverse <-- {hypreal,hcomplex}_inverse
   620   star_n_le <-- {hypreal,hypnat}_le
   621   star_n_less <-- {hypreal,hypnat}_less
   622   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
   623   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
   624   star_n_abs <-- hypreal_hrabs
   625   star_n_divide <-- hcomplex_divide
   626 
   627   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
   628   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
   629   star_of_diff <-- hypreal_of_real_diff
   630   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
   631   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
   632   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
   633   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
   634   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
   635   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
   636   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
   637   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
   638   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
   639   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
   640   star_of_number_of <-- {hypreal,hcomplex}_number_of
   641   star_of_number_less <-- number_of_less_hypreal_of_real_iff
   642   star_of_number_le <-- number_of_le_hypreal_of_real_iff
   643   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
   644   star_of_less_number <-- hypreal_of_real_less_number_of_iff
   645   star_of_le_number <-- hypreal_of_real_le_number_of_iff
   646   star_of_power <-- hypreal_of_real_power
   647   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
   648 
   649 * Hyperreal: new method "transfer" that implements the transfer
   650 principle of nonstandard analysis. With a subgoal that mentions
   651 nonstandard types like "'a star", the command "apply transfer"
   652 replaces it with an equivalent one that mentions only standard types.
   653 To be successful, all free variables must have standard types; non-
   654 standard variables must have explicit universal quantifiers.
   655 
   656 
   657 *** HOLCF ***
   658 
   659 * Discontinued special version of 'constdefs' (which used to support
   660 continuous functions) in favor of the general Pure one with full
   661 type-inference.
   662 
   663 * New simplification procedure for solving continuity conditions; it
   664 is much faster on terms with many nested lambda abstractions (cubic
   665 instead of exponential time).
   666 
   667 * New syntax for domain package: selector names are now optional.
   668 Parentheses should be omitted unless argument is lazy, for example:
   669 
   670   domain 'a stream = cons "'a" (lazy "'a stream")
   671 
   672 * New command 'fixrec' for defining recursive functions with pattern
   673 matching; defining multiple functions with mutual recursion is also
   674 supported.  Patterns may include the constants cpair, spair, up, sinl,
   675 sinr, or any data constructor defined by the domain package. The given
   676 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
   677 syntax and examples.
   678 
   679 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
   680 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
   681 but the proof obligation additionally includes an admissibility
   682 requirement. The packages generate instances of class cpo or pcpo,
   683 with continuity and strictness theorems for Rep and Abs.
   684 
   685 * HOLCF: Many theorems have been renamed according to a more standard naming
   686 scheme (INCOMPATIBILITY):
   687 
   688   foo_inject:  "foo$x = foo$y ==> x = y"
   689   foo_eq:      "(foo$x = foo$y) = (x = y)"
   690   foo_less:    "(foo$x << foo$y) = (x << y)"
   691   foo_strict:  "foo$UU = UU"
   692   foo_defined: "... ==> foo$x ~= UU"
   693   foo_defined_iff: "(foo$x = UU) = (x = UU)"
   694 
   695 
   696 *** ZF ***
   697 
   698 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
   699 including the First Isomorphism Theorem (on quotienting by the kernel
   700 of a homomorphism).
   701 
   702 * ZF/Simplifier: install second copy of type solver that actually
   703 makes use of TC rules declared to Isar proof contexts (or locales);
   704 the old version is still required for ML proof scripts.
   705 
   706 
   707 *** Cube ***
   708 
   709 * Converted to Isar theory format; use locales instead of axiomatic
   710 theories.
   711 
   712 
   713 *** ML ***
   714 
   715 * Pure/library.ML no longer defines its own option datatype, but uses
   716 that of the SML basis, which has constructors NONE and SOME instead of
   717 None and Some, as well as exception Option.Option instead of OPTION.
   718 The functions the, if_none, is_some, is_none have been adapted
   719 accordingly, while Option.map replaces apsome.
   720 
   721 * Pure/library.ML: the exception LIST has been given up in favour of
   722 the standard exceptions Empty and Subscript, as well as
   723 Library.UnequalLengths.  Function like Library.hd and Library.tl are
   724 superceded by the standard hd and tl functions etc.
   725 
   726 A number of basic list functions are no longer exported to the ML
   727 toplevel, as they are variants of predefined functions.  The following
   728 suggests how one can translate existing code:
   729 
   730     rev_append xs ys = List.revAppend (xs, ys)
   731     nth_elem (i, xs) = List.nth (xs, i)
   732     last_elem xs = List.last xs
   733     flat xss = List.concat xss
   734     seq fs = List.app fs
   735     partition P xs = List.partition P xs
   736     mapfilter f xs = List.mapPartial f xs
   737 
   738 * Pure/library.ML: several combinators for linear functional
   739 transformations, notably reverse application and composition:
   740 
   741   x |> f                f #> g
   742   (x, y) |-> f          f #-> g
   743 
   744 * Pure/library.ML: introduced/changed precedence of infix operators:
   745 
   746   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
   747   infix 2 ?;
   748   infix 3 o oo ooo oooo;
   749   infix 4 ~~ upto downto;
   750 
   751 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
   752 infix operators.
   753 
   754 * Pure/library.ML: natural list combinators fold, fold_rev, and
   755 fold_map support linear functional transformations and nesting.  For
   756 example:
   757 
   758   fold f [x1, ..., xN] y =
   759     y |> f x1 |> ... |> f xN
   760 
   761   (fold o fold) f [xs1, ..., xsN] y =
   762     y |> fold f xs1 |> ... |> fold f xsN
   763 
   764   fold f [x1, ..., xN] =
   765     f x1 #> ... #> f xN
   766 
   767   (fold o fold) f [xs1, ..., xsN] =
   768     fold f xs1 #> ... #> fold f xsN
   769 
   770 * Pure/library.ML: the following selectors on type 'a option are
   771 available:
   772 
   773   the:               'a option -> 'a  (*partial*)
   774   these:             'a option -> 'a  where 'a = 'b list
   775   the_default: 'a -> 'a option -> 'a
   776   the_list:          'a option -> 'a list
   777 
   778 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
   779 basic operations for association lists, following natural argument
   780 order; moreover the explicit equality predicate passed here avoids
   781 potentially expensive polymorphic runtime equality checks.
   782 The old functions may be expressed as follows:
   783 
   784   assoc = uncurry (AList.lookup (op =))
   785   assocs = these oo AList.lookup (op =)
   786   overwrite = uncurry (AList.update (op =)) o swap
   787 
   788 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
   789 
   790   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
   791   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
   792 
   793 replacing make_keylist and keyfilter (occassionally used)
   794 Naive rewrites:
   795 
   796   make_keylist = AList.make
   797   keyfilter = AList.find (op =)
   798 
   799 * eq_fst and eq_snd now take explicit equality parameter, thus
   800   avoiding eqtypes. Naive rewrites:
   801 
   802     eq_fst = eq_fst (op =)
   803     eq_snd = eq_snd (op =)
   804 
   805 * Removed deprecated apl and apr (rarely used).
   806   Naive rewrites:
   807 
   808     apl (n, op) =>>= curry op n
   809     apr (op, m) =>>= fn n => op (n, m)
   810 
   811 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
   812 provides a reasonably efficient light-weight implementation of sets as
   813 lists.
   814 
   815 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
   816 few new operations; existing lookup and update are now curried to
   817 follow natural argument order (for use with fold etc.);
   818 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
   819 
   820 * Pure/General: output via the Isabelle channels of
   821 writeln/warning/error etc. is now passed through Output.output, with a
   822 hook for arbitrary transformations depending on the print_mode
   823 (cf. Output.add_mode -- the first active mode that provides a output
   824 function wins).  Already formatted output may be embedded into further
   825 text via Output.raw; the result of Pretty.string_of/str_of and derived
   826 functions (string_of_term/cterm/thm etc.) is already marked raw to
   827 accommodate easy composition of diagnostic messages etc.  Programmers
   828 rarely need to care about Output.output or Output.raw at all, with
   829 some notable exceptions: Output.output is required when bypassing the
   830 standard channels (writeln etc.), or in token translations to produce
   831 properly formatted results; Output.raw is required when capturing
   832 already output material that will eventually be presented to the user
   833 a second time.  For the default print mode, both Output.output and
   834 Output.raw have no effect.
   835 
   836 * Pure/General: Output.time_accumulator NAME creates an operator ('a
   837 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
   838 cumulative results are displayed at the end of a batch session.
   839 
   840 * Pure/General: File.sysify_path and File.quote_sysify path have been
   841 replaced by File.platform_path and File.shell_path (with appropriate
   842 hooks).  This provides a clean interface for unusual systems where the
   843 internal and external process view of file names are different.
   844 
   845 * Pure: more efficient orders for basic syntactic entities: added
   846 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
   847 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
   848 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
   849 orders now -- potential INCOMPATIBILITY for code that depends on a
   850 particular order for Symtab.keys, Symtab.dest, etc. (consider using
   851 Library.sort_strings on result).
   852 
   853 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
   854 fold_types traverse types/terms from left to right, observing natural
   855 argument order.  Supercedes previous foldl_XXX versions, add_frees,
   856 add_vars etc. have been adapted as well: INCOMPATIBILITY.
   857 
   858 * Pure: name spaces have been refined, with significant changes of the
   859 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
   860 to extern(_table).  The plain name entry path is superceded by a
   861 general 'naming' context, which also includes the 'policy' to produce
   862 a fully qualified name and external accesses of a fully qualified
   863 name; NameSpace.extend is superceded by context dependent
   864 Sign.declare_name.  Several theory and proof context operations modify
   865 the naming context.  Especially note Theory.restore_naming and
   866 ProofContext.restore_naming to get back to a sane state; note that
   867 Theory.add_path is no longer sufficient to recover from
   868 Theory.absolute_path in particular.
   869 
   870 * Pure: new flags short_names (default false) and unique_names
   871 (default true) for controlling output of qualified names.  If
   872 short_names is set, names are printed unqualified.  If unique_names is
   873 reset, the name prefix is reduced to the minimum required to achieve
   874 the original result when interning again, even if there is an overlap
   875 with earlier declarations.
   876 
   877 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
   878 now 'extend', and 'merge' gets an additional Pretty.pp argument
   879 (useful for printing error messages).  INCOMPATIBILITY.
   880 
   881 * Pure: major reorganization of the theory context.  Type Sign.sg and
   882 Theory.theory are now identified, referring to the universal
   883 Context.theory (see Pure/context.ML).  Actual signature and theory
   884 content is managed as theory data.  The old code and interfaces were
   885 spread over many files and structures; the new arrangement introduces
   886 considerable INCOMPATIBILITY to gain more clarity:
   887 
   888   Context -- theory management operations (name, identity, inclusion,
   889     parents, ancestors, merge, etc.), plus generic theory data;
   890 
   891   Sign -- logical signature and syntax operations (declaring consts,
   892     types, etc.), plus certify/read for common entities;
   893 
   894   Theory -- logical theory operations (stating axioms, definitions,
   895     oracles), plus a copy of logical signature operations (consts,
   896     types, etc.); also a few basic management operations (Theory.copy,
   897     Theory.merge, etc.)
   898 
   899 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
   900 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
   901 for convenience -- they merely return the theory.
   902 
   903 * Pure: type Type.tsig is superceded by theory in most interfaces.
   904 
   905 * Pure: the Isar proof context type is already defined early in Pure
   906 as Context.proof (note that ProofContext.context and Proof.context are
   907 aliases, where the latter is the preferred name).  This enables other
   908 Isabelle components to refer to that type even before Isar is present.
   909 
   910 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
   911 typeK, constK, axiomK, oracleK), but provide explicit operations for
   912 any of these kinds.  For example, Sign.intern typeK is now
   913 Sign.intern_type, Theory.hide_space Sign.typeK is now
   914 Theory.hide_types.  Also note that former
   915 Theory.hide_classes/types/consts are now
   916 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
   917 internalize their arguments!  INCOMPATIBILITY.
   918 
   919 * Pure: get_thm interface (of PureThy and ProofContext) expects
   920 datatype thmref (with constructors Name and NameSelection) instead of
   921 plain string -- INCOMPATIBILITY;
   922 
   923 * Pure: cases produced by proof methods specify options, where NONE
   924 means to remove case bindings -- INCOMPATIBILITY in
   925 (RAW_)METHOD_CASES.
   926 
   927 * Pure: the following operations retrieve axioms or theorems from a
   928 theory node or theory hierarchy, respectively:
   929 
   930   Theory.axioms_of: theory -> (string * term) list
   931   Theory.all_axioms_of: theory -> (string * term) list
   932   PureThy.thms_of: theory -> (string * thm) list
   933   PureThy.all_thms_of: theory -> (string * thm) list
   934 
   935 * Pure: print_tac now outputs the goal through the trace channel.
   936 
   937 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
   938 Reference Toplevel.debug (default false) controls detailed printing
   939 and tracing of low-level exceptions; Toplevel.profiling (default 0)
   940 controls execution profiling -- set to 1 for time and 2 for space
   941 (both increase the runtime).
   942 
   943 * Isar session: The initial use of ROOT.ML is now always timed,
   944 i.e. the log will show the actual process times, in contrast to the
   945 elapsed wall-clock time that the outer shell wrapper produces.
   946 
   947 * Simplifier: improved handling of bound variables (nameless
   948 representation, avoid allocating new strings).  Simprocs that invoke
   949 the Simplifier recursively should use Simplifier.inherit_bounds to
   950 avoid local name clashes.
   951 
   952 * Provers: Simplifier and Classical Reasoner now support proof context
   953 dependent plug-ins (simprocs, solvers, wrappers etc.).  These extra
   954 components are stored in the theory and patched into the
   955 simpset/claset when used in an Isar proof context.  Context dependent
   956 components are maintained by the following theory operations:
   957 
   958   Simplifier.add_context_simprocs
   959   Simplifier.del_context_simprocs
   960   Simplifier.set_context_subgoaler
   961   Simplifier.reset_context_subgoaler
   962   Simplifier.add_context_looper
   963   Simplifier.del_context_looper
   964   Simplifier.add_context_unsafe_solver
   965   Simplifier.add_context_safe_solver
   966 
   967   Classical.add_context_safe_wrapper
   968   Classical.del_context_safe_wrapper
   969   Classical.add_context_unsafe_wrapper
   970   Classical.del_context_unsafe_wrapper
   971 
   972 IMPORTANT NOTE: proof tools (methods etc.) need to use
   973 local_simpset_of and local_claset_of to instead of the primitive
   974 Simplifier.get_local_simpset and Classical.get_local_claset,
   975 respectively, in order to see the context dependent fields!
   976 
   977 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
   978 bindings for all theorems stored within a given theory; this may help
   979 in porting non-Isar theories to Isar ones, while keeping ML proof
   980 scripts for the time being.
   981 
   982 * ML operator HTML.with_charset specifies the charset begin used for
   983 generated HTML files.  For example:
   984 
   985   HTML.with_charset "utf-8" use_thy "Hebrew";
   986   HTML.with_charset "utf-8" use_thy "Chinese";
   987 
   988 
   989 *** System ***
   990 
   991 * Allow symlinks to all proper Isabelle executables (Isabelle,
   992 isabelle, isatool etc.).
   993 
   994 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
   995 isatool doc, isatool mkdir, display_drafts etc.).
   996 
   997 * isatool usedir: option -f allows specification of the ML file to be
   998 used by Isabelle; default is ROOT.ML.
   999 
  1000 * New isatool version outputs the version identifier of the Isabelle
  1001 distribution being used.
  1002 
  1003 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  1004 (containing Boolean satisfiability problems) into Isabelle/HOL
  1005 theories.
  1006 
  1007 
  1008 
  1009 New in Isabelle2004 (April 2004)
  1010 --------------------------------
  1011 
  1012 *** General ***
  1013 
  1014 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  1015   Replaces linorder.ML.
  1016 
  1017 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  1018   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  1019   (\<a>...\<z>), are now considered normal letters, and can therefore
  1020   be used anywhere where an ASCII letter (a...zA...Z) has until
  1021   now. COMPATIBILITY: This obviously changes the parsing of some
  1022   terms, especially where a symbol has been used as a binder, say
  1023   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  1024   as an identifier.  Fix it by inserting a space around former
  1025   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  1026   existing theory and ML files.
  1027 
  1028 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  1029 
  1030 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  1031   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  1032   a normal (but invisible) letter. For multiple letter subscripts repeat
  1033   \<^isub> like this: x\<^isub>1\<^isub>2.
  1034 
  1035 * Pure: There are now sub-/superscripts that can span more than one
  1036   character. Text between \<^bsub> and \<^esub> is set in subscript in
  1037   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  1038   superscript. The new control characters are not identifier parts.
  1039 
  1040 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  1041   content of "..." to the latex file instead of \isacntrl... . The "..."
  1042   may consist of any printable characters excluding the end bracket >.
  1043 
  1044 * Pure: Using new Isar command "finalconsts" (or the ML functions
  1045   Theory.add_finals or Theory.add_finals_i) it is now possible to
  1046   declare constants "final", which prevents their being given a definition
  1047   later.  It is useful for constants whose behaviour is fixed axiomatically
  1048   rather than definitionally, such as the meta-logic connectives.
  1049 
  1050 * Pure: 'instance' now handles general arities with general sorts
  1051   (i.e. intersections of classes),
  1052 
  1053 * Presentation: generated HTML now uses a CSS style sheet to make layout
  1054   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  1055   It can be changed to alter the colors/layout of generated pages.
  1056 
  1057 
  1058 *** Isar ***
  1059 
  1060 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  1061   cut_tac, subgoal_tac and thin_tac:
  1062   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  1063     locales are no longer forced to write Isar proof scripts.
  1064     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  1065     emulations.
  1066   - INCOMPATIBILITY: names of variables to be instantiated may no
  1067     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  1068     This is consistent with the instantiation attribute "where".
  1069 
  1070 * Attributes "where" and "of":
  1071   - Now take type variables of instantiated theorem into account when reading
  1072     the instantiation string.  This fixes a bug that caused instantiated
  1073     theorems to have too special types in some circumstances.
  1074   - "where" permits explicit instantiations of type variables.
  1075 
  1076 * Calculation commands "moreover" and "also" no longer interfere with
  1077   current facts ("this"), admitting arbitrary combinations with "then"
  1078   and derived forms.
  1079 
  1080 * Locales:
  1081   - Goal statements involving the context element "includes" no longer
  1082     generate theorems with internal delta predicates (those ending on
  1083     "_axioms") in the premise.
  1084     Resolve particular premise with <locale>.intro to obtain old form.
  1085   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  1086     specification and "includes" elements in goal statement.
  1087   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  1088     [intro?] and [elim?] (respectively) by default.
  1089   - Experimental command for instantiation of locales in proof contexts:
  1090         instantiate <label>[<attrs>]: <loc>
  1091     Instantiates locale <loc> and adds all its theorems to the current context
  1092     taking into account their attributes.  Label and attrs are optional
  1093     modifiers, like in theorem declarations.  If present, names of
  1094     instantiated theorems are qualified with <label>, and the attributes
  1095     <attrs> are applied after any attributes these theorems might have already.
  1096       If the locale has assumptions, a chained fact of the form
  1097     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  1098     are derived.  The command does not support old-style locales declared
  1099     with "locale (open)".
  1100       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  1101 
  1102 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  1103   (Isar) contexts.
  1104 
  1105 
  1106 *** HOL ***
  1107 
  1108 * Proof import: new image HOL4 contains the imported library from
  1109   the HOL4 system with about 2500 theorems. It is imported by
  1110   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  1111   can be used like any other Isabelle image.  See
  1112   HOL/Import/HOL/README for more information.
  1113 
  1114 * Simplifier:
  1115   - Much improved handling of linear and partial orders.
  1116     Reasoners for linear and partial orders are set up for type classes
  1117     "linorder" and "order" respectively, and are added to the default simpset
  1118     as solvers.  This means that the simplifier can build transitivity chains
  1119     to solve goals from the assumptions.
  1120   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  1121     of blast or auto after simplification become unnecessary because the goal
  1122     is solved by simplification already.
  1123 
  1124 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  1125     all proved in axiomatic type classes for semirings, rings and fields.
  1126 
  1127 * Numerics:
  1128   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  1129     now formalized using the Ring_and_Field theory mentioned above.
  1130   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  1131     than before, because now they are set up once in a generic manner.
  1132   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  1133     Look for the general versions in Ring_and_Field (and Power if they concern
  1134     exponentiation).
  1135 
  1136 * Type "rat" of the rational numbers is now available in HOL-Complex.
  1137 
  1138 * Records:
  1139   - Record types are now by default printed with their type abbreviation
  1140     instead of the list of all field types. This can be configured via
  1141     the reference "print_record_type_abbr".
  1142   - Simproc "record_upd_simproc" for simplification of multiple updates added
  1143     (not enabled by default).
  1144   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  1145     EX x. x = sel r to True (not enabled by default).
  1146   - Tactic "record_split_simp_tac" to split and simplify records added.
  1147 
  1148 * 'specification' command added, allowing for definition by
  1149   specification.  There is also an 'ax_specification' command that
  1150   introduces the new constants axiomatically.
  1151 
  1152 * arith(_tac) is now able to generate counterexamples for reals as well.
  1153 
  1154 * HOL-Algebra: new locale "ring" for non-commutative rings.
  1155 
  1156 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  1157   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  1158 
  1159 * HOL-Matrix: a first theory for matrices in HOL with an application of
  1160   matrix theory to linear programming.
  1161 
  1162 * Unions and Intersections:
  1163   The latex output syntax of UN and INT has been changed
  1164   from "\Union x \in A. B" to "\Union_{x \in A} B"
  1165   i.e. the index formulae has become a subscript.
  1166   Similarly for "\Union x. B", and for \Inter instead of \Union.
  1167 
  1168 * Unions and Intersections over Intervals:
  1169   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  1170   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  1171   like in normal math, and corresponding versions for < and for intersection.
  1172 
  1173 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  1174   lexicographic dictonary ordering has been added as "lexord".
  1175 
  1176 * ML: the legacy theory structures Int and List have been removed. They had
  1177   conflicted with ML Basis Library structures having the same names.
  1178 
  1179 * 'refute' command added to search for (finite) countermodels.  Only works
  1180   for a fragment of HOL.  The installation of an external SAT solver is
  1181   highly recommended.  See "HOL/Refute.thy" for details.
  1182 
  1183 * 'quickcheck' command: Allows to find counterexamples by evaluating
  1184   formulae under an assignment of free variables to random values.
  1185   In contrast to 'refute', it can deal with inductive datatypes,
  1186   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  1187   for examples.
  1188 
  1189 
  1190 *** HOLCF ***
  1191 
  1192 * Streams now come with concatenation and are part of the HOLCF image
  1193 
  1194 
  1195 
  1196 New in Isabelle2003 (May 2003)
  1197 ------------------------------
  1198 
  1199 *** General ***
  1200 
  1201 * Provers/simplifier:
  1202 
  1203   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  1204     Assumptions are now subject to complete mutual simplification,
  1205     not just from left to right. The simplifier now preserves
  1206     the order of assumptions.
  1207 
  1208     Potential INCOMPATIBILITY:
  1209 
  1210     -- simp sometimes diverges where the old version did
  1211        not, e.g. invoking simp on the goal
  1212 
  1213         [| P (f x); y = x; f x = f y |] ==> Q
  1214 
  1215        now gives rise to the infinite reduction sequence
  1216 
  1217         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  1218 
  1219        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  1220        kind of problem.
  1221 
  1222     -- Tactics combining classical reasoner and simplification (such as auto)
  1223        are also affected by this change, because many of them rely on
  1224        simp. They may sometimes diverge as well or yield a different numbers
  1225        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  1226        in case of problems. Sometimes subsequent calls to the classical
  1227        reasoner will fail because a preceeding call to the simplifier too
  1228        eagerly simplified the goal, e.g. deleted redundant premises.
  1229 
  1230   - The simplifier trace now shows the names of the applied rewrite rules
  1231 
  1232   - You can limit the number of recursive invocations of the simplifier
  1233     during conditional rewriting (where the simplifie tries to solve the
  1234     conditions before applying the rewrite rule):
  1235     ML "simp_depth_limit := n"
  1236     where n is an integer. Thus you can force termination where previously
  1237     the simplifier would diverge.
  1238 
  1239   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  1240 
  1241   - No longer aborts on failed congruence proof.  Instead, the
  1242     congruence is ignored.
  1243 
  1244 * Pure: New generic framework for extracting programs from constructive
  1245   proofs. See HOL/Extraction.thy for an example instantiation, as well
  1246   as HOL/Extraction for some case studies.
  1247 
  1248 * Pure: The main goal of the proof state is no longer shown by default, only
  1249 the subgoals. This behaviour is controlled by a new flag.
  1250    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  1251 (ML: Proof.show_main_goal).
  1252 
  1253 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  1254 rules whose conclusion matches subgoal 1:
  1255       PG menu: Isabelle/Isar -> Show me -> matching rules
  1256 The rules are ordered by how closely they match the subgoal.
  1257 In particular, rules that solve a subgoal outright are displayed first
  1258 (or rather last, the way they are printed).
  1259 (ML: ProofGeneral.print_intros())
  1260 
  1261 * Pure: New flag trace_unify_fail causes unification to print
  1262 diagnostic information (PG: in trace buffer) when it fails. This is
  1263 useful for figuring out why single step proofs like rule, erule or
  1264 assumption failed.
  1265 
  1266 * Pure: Locale specifications now produce predicate definitions
  1267 according to the body of text (covering assumptions modulo local
  1268 definitions); predicate "loc_axioms" covers newly introduced text,
  1269 while "loc" is cumulative wrt. all included locale expressions; the
  1270 latter view is presented only on export into the global theory
  1271 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  1272 on the old view without predicates;
  1273 
  1274 * Pure: predefined locales "var" and "struct" are useful for sharing
  1275 parameters (as in CASL, for example); just specify something like
  1276 ``var x + var y + struct M'' as import;
  1277 
  1278 * Pure: improved thms_containing: proper indexing of facts instead of
  1279 raw theorems; check validity of results wrt. current name space;
  1280 include local facts of proof configuration (also covers active
  1281 locales), cover fixed variables in index; may use "_" in term
  1282 specification; an optional limit for the number of printed facts may
  1283 be given (the default is 40);
  1284 
  1285 * Pure: disallow duplicate fact bindings within new-style theory files
  1286 (batch-mode only);
  1287 
  1288 * Provers: improved induct method: assumptions introduced by case
  1289 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  1290 the goal statement); "foo" still refers to all facts collectively;
  1291 
  1292 * Provers: the function blast.overloaded has been removed: all constants
  1293 are regarded as potentially overloaded, which improves robustness in exchange
  1294 for slight decrease in efficiency;
  1295 
  1296 * Provers/linorder: New generic prover for transitivity reasoning over
  1297 linear orders.  Note: this prover is not efficient!
  1298 
  1299 * Isar: preview of problems to finish 'show' now produce an error
  1300 rather than just a warning (in interactive mode);
  1301 
  1302 
  1303 *** HOL ***
  1304 
  1305 * arith(_tac)
  1306 
  1307  - Produces a counter example if it cannot prove a goal.
  1308    Note that the counter example may be spurious if the goal is not a formula
  1309    of quantifier-free linear arithmetic.
  1310    In ProofGeneral the counter example appears in the trace buffer.
  1311 
  1312  - Knows about div k and mod k where k is a numeral of type nat or int.
  1313 
  1314  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  1315    linear arithmetic fails. This takes account of quantifiers and divisibility.
  1316    Presburger arithmetic can also be called explicitly via presburger(_tac).
  1317 
  1318 * simp's arithmetic capabilities have been enhanced a bit: it now
  1319 takes ~= in premises into account (by performing a case split);
  1320 
  1321 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  1322 are distributed over a sum of terms;
  1323 
  1324 * New tactic "trans_tac" and method "trans" instantiate
  1325 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  1326 "<=", "<" and "=").
  1327 
  1328 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  1329 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  1330 
  1331 * 'typedef' command has new option "open" to suppress the set
  1332 definition;
  1333 
  1334 * functions Min and Max on finite sets have been introduced (theory
  1335 Finite_Set);
  1336 
  1337 * attribute [symmetric] now works for relations as well; it turns
  1338 (x,y) : R^-1 into (y,x) : R, and vice versa;
  1339 
  1340 * induct over a !!-quantified statement (say !!x1..xn):
  1341   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  1342 
  1343 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  1344 %x. None. Warning: empty_def now refers to the previously hidden definition
  1345 of the empty set.
  1346 
  1347 * Algebra: formalization of classical algebra.  Intended as base for
  1348 any algebraic development in Isabelle.  Currently covers group theory
  1349 (up to Sylow's theorem) and ring theory (Universal Property of
  1350 Univariate Polynomials).  Contributions welcome;
  1351 
  1352 * GroupTheory: deleted, since its material has been moved to Algebra;
  1353 
  1354 * Complex: new directory of the complex numbers with numeric constants,
  1355 nonstandard complex numbers, and some complex analysis, standard and
  1356 nonstandard (Jacques Fleuriot);
  1357 
  1358 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  1359 
  1360 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  1361 Fleuriot);
  1362 
  1363 * Real/HahnBanach: updated and adapted to locales;
  1364 
  1365 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  1366 Gray and Kramer);
  1367 
  1368 * UNITY: added the Meier-Sanders theory of progress sets;
  1369 
  1370 * MicroJava: bytecode verifier and lightweight bytecode verifier
  1371 as abstract algorithms, instantiated to the JVM;
  1372 
  1373 * Bali: Java source language formalization. Type system, operational
  1374 semantics, axiomatic semantics. Supported language features:
  1375 classes, interfaces, objects,virtual methods, static methods,
  1376 static/instance fields, arrays, access modifiers, definite
  1377 assignment, exceptions.
  1378 
  1379 
  1380 *** ZF ***
  1381 
  1382 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  1383 universe, etc.);
  1384 
  1385 * Main ZF: virtually all theories converted to new-style format;
  1386 
  1387 
  1388 *** ML ***
  1389 
  1390 * Pure: Tactic.prove provides sane interface for internal proofs;
  1391 omits the infamous "standard" operation, so this is more appropriate
  1392 than prove_goalw_cterm in many situations (e.g. in simprocs);
  1393 
  1394 * Pure: improved error reporting of simprocs;
  1395 
  1396 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  1397 up simprocs;
  1398 
  1399 
  1400 *** Document preparation ***
  1401 
  1402 * uses \par instead of \\ for line breaks in theory text. This may
  1403 shift some page breaks in large documents. To get the old behaviour
  1404 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  1405 
  1406 * minimized dependencies of isabelle.sty and isabellesym.sty on
  1407 other packages
  1408 
  1409 * \<euro> now needs package babel/greek instead of marvosym (which
  1410 broke \Rightarrow)
  1411 
  1412 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  1413 textcomp package)
  1414 
  1415 
  1416 
  1417 New in Isabelle2002 (March 2002)
  1418 --------------------------------
  1419 
  1420 *** Document preparation ***
  1421 
  1422 * greatly simplified document preparation setup, including more
  1423 graceful interpretation of isatool usedir -i/-d/-D options, and more
  1424 instructive isatool mkdir; users should basically be able to get
  1425 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  1426 users may run a separate document processing stage manually like this:
  1427 "isatool usedir -D output HOL Test && isatool document Test/output";
  1428 
  1429 * theory dependency graph may now be incorporated into documents;
  1430 isatool usedir -g true will produce session_graph.eps/.pdf for use
  1431 with \includegraphics of LaTeX;
  1432 
  1433 * proper spacing of consecutive markup elements, especially text
  1434 blocks after section headings;
  1435 
  1436 * support bold style (for single symbols only), input syntax is like
  1437 this: "\<^bold>\<alpha>" or "\<^bold>A";
  1438 
  1439 * \<bullet> is now output as bold \cdot by default, which looks much
  1440 better in printed text;
  1441 
  1442 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  1443 note that these symbols are currently unavailable in Proof General /
  1444 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  1445 
  1446 * isatool latex no longer depends on changed TEXINPUTS, instead
  1447 isatool document copies the Isabelle style files to the target
  1448 location;
  1449 
  1450 
  1451 *** Isar ***
  1452 
  1453 * Pure/Provers: improved proof by cases and induction;
  1454   - 'case' command admits impromptu naming of parameters (such as
  1455     "case (Suc n)");
  1456   - 'induct' method divinates rule instantiation from the inductive
  1457     claim; no longer requires excessive ?P bindings for proper
  1458     instantiation of cases;
  1459   - 'induct' method properly enumerates all possibilities of set/type
  1460     rules; as a consequence facts may be also passed through *type*
  1461     rules without further ado;
  1462   - 'induct' method now derives symbolic cases from the *rulified*
  1463     rule (before it used to rulify cases stemming from the internal
  1464     atomized version); this means that the context of a non-atomic
  1465     statement becomes is included in the hypothesis, avoiding the
  1466     slightly cumbersome show "PROP ?case" form;
  1467   - 'induct' may now use elim-style induction rules without chaining
  1468     facts, using ``missing'' premises from the goal state; this allows
  1469     rules stemming from inductive sets to be applied in unstructured
  1470     scripts, while still benefitting from proper handling of non-atomic
  1471     statements; NB: major inductive premises need to be put first, all
  1472     the rest of the goal is passed through the induction;
  1473   - 'induct' proper support for mutual induction involving non-atomic
  1474     rule statements (uses the new concept of simultaneous goals, see
  1475     below);
  1476   - append all possible rule selections, but only use the first
  1477     success (no backtracking);
  1478   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  1479   - undeclared rule case names default to numbers 1, 2, 3, ...;
  1480   - added 'print_induct_rules' (covered by help item in recent Proof
  1481     General versions);
  1482   - moved induct/cases attributes to Pure, methods to Provers;
  1483   - generic method setup instantiated for FOL and HOL;
  1484 
  1485 * Pure: support multiple simultaneous goal statements, for example
  1486 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  1487 meta-level mechanism, this acts as if several individual goals had
  1488 been stated separately; in particular common proof methods need to be
  1489 repeated in order to cover all claims; note that a single elimination
  1490 step is *not* sufficient to establish the two conjunctions, so this
  1491 fails:
  1492 
  1493   assume "A & B" then have A and B ..   (*".." fails*)
  1494 
  1495 better use "obtain" in situations as above; alternative refer to
  1496 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  1497 
  1498 * Pure: proper integration with ``locales''; unlike the original
  1499 version by Florian Kammller, Isar locales package high-level proof
  1500 contexts rather than raw logical ones (e.g. we admit to include
  1501 attributes everywhere); operations on locales include merge and
  1502 rename; support for implicit arguments (``structures''); simultaneous
  1503 type-inference over imports and text; see also HOL/ex/Locales.thy for
  1504 some examples;
  1505 
  1506 * Pure: the following commands have been ``localized'', supporting a
  1507 target locale specification "(in name)": 'lemma', 'theorem',
  1508 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  1509 stored both within the locale and at the theory level (exported and
  1510 qualified by the locale name);
  1511 
  1512 * Pure: theory goals may now be specified in ``long'' form, with
  1513 ad-hoc contexts consisting of arbitrary locale elements. for example
  1514 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  1515 definitions may be given, too); the result is a meta-level rule with
  1516 the context elements being discharged in the obvious way;
  1517 
  1518 * Pure: new proof command 'using' allows to augment currently used
  1519 facts after a goal statement ('using' is syntactically analogous to
  1520 'apply', but acts on the goal's facts only); this allows chained facts
  1521 to be separated into parts given before and after a claim, as in
  1522 ``from a and b have C using d and e <proof>'';
  1523 
  1524 * Pure: renamed "antecedent" case to "rule_context";
  1525 
  1526 * Pure: new 'judgment' command records explicit information about the
  1527 object-logic embedding (used by several tools internally); no longer
  1528 use hard-wired "Trueprop";
  1529 
  1530 * Pure: added 'corollary' command;
  1531 
  1532 * Pure: fixed 'token_translation' command;
  1533 
  1534 * Pure: removed obsolete 'exported' attribute;
  1535 
  1536 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  1537 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  1538 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  1539 
  1540 * Pure: method 'atomize' presents local goal premises as object-level
  1541 statements (atomic meta-level propositions); setup controlled via
  1542 rewrite rules declarations of 'atomize' attribute; example
  1543 application: 'induct' method with proper rule statements in improper
  1544 proof *scripts*;
  1545 
  1546 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  1547 now consider the syntactic context of assumptions, giving a better
  1548 chance to get type-inference of the arguments right (this is
  1549 especially important for locales);
  1550 
  1551 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  1552 mode;
  1553 
  1554 * Pure/obtain: the formal conclusion "thesis", being marked as
  1555 ``internal'', may no longer be reference directly in the text;
  1556 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  1557 situations;
  1558 
  1559 * Pure: generic 'sym' attribute which declares a rule both as pure
  1560 'elim?' and for the 'symmetric' operation;
  1561 
  1562 * Pure: marginal comments ``--'' may now occur just anywhere in the
  1563 text; the fixed correlation with particular command syntax has been
  1564 discontinued;
  1565 
  1566 * Pure: new method 'rules' is particularly well-suited for proof
  1567 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  1568 but often produces more compact proof terms with less detours;
  1569 
  1570 * Pure/Provers/classical: simplified integration with pure rule
  1571 attributes and methods; the classical "intro?/elim?/dest?"
  1572 declarations coincide with the pure ones; the "rule" method no longer
  1573 includes classically swapped intros; "intro" and "elim" methods no
  1574 longer pick rules from the context; also got rid of ML declarations
  1575 AddXIs/AddXEs/AddXDs; all of this has some potential for
  1576 INCOMPATIBILITY;
  1577 
  1578 * Provers/classical: attribute 'swapped' produces classical inversions
  1579 of introduction rules;
  1580 
  1581 * Provers/simplifier: 'simplified' attribute may refer to explicit
  1582 rules instead of full simplifier context; 'iff' attribute handles
  1583 conditional rules;
  1584 
  1585 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  1586 
  1587 * HOL: 'recdef' now fails on unfinished automated proofs, use
  1588 "(permissive)" option to recover old behavior;
  1589 
  1590 * HOL: 'inductive' no longer features separate (collective) attributes
  1591 for 'intros' (was found too confusing);
  1592 
  1593 * HOL: properly declared induction rules less_induct and
  1594 wf_induct_rule;
  1595 
  1596 
  1597 *** HOL ***
  1598 
  1599 * HOL: moved over to sane numeral syntax; the new policy is as
  1600 follows:
  1601 
  1602   - 0 and 1 are polymorphic constants, which are defined on any
  1603   numeric type (nat, int, real etc.);
  1604 
  1605   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  1606   binary representation internally;
  1607 
  1608   - type nat has special constructor Suc, and generally prefers Suc 0
  1609   over 1::nat and Suc (Suc 0) over 2::nat;
  1610 
  1611 This change may cause significant problems of INCOMPATIBILITY; here
  1612 are some hints on converting existing sources:
  1613 
  1614   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  1615   entities, so expressions involving "-" (unary or binary minus) need
  1616   to be spaced properly;
  1617 
  1618   - existing occurrences of "1" may need to be constraint "1::nat" or
  1619   even replaced by Suc 0; similar for old "2";
  1620 
  1621   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  1622 
  1623   - remove all special provisions on numerals in proofs;
  1624 
  1625 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  1626 representation (depends on bin_arith_simps in the default context);
  1627 
  1628 * HOL: symbolic syntax for x^2 (numeral 2);
  1629 
  1630 * HOL: the class of all HOL types is now called "type" rather than
  1631 "term"; INCOMPATIBILITY, need to adapt references to this type class
  1632 in axclass/classes, instance/arities, and (usually rare) occurrences
  1633 in typings (of consts etc.); internally the class is called
  1634 "HOL.type", ML programs should refer to HOLogic.typeS;
  1635 
  1636 * HOL/record package improvements:
  1637   - new derived operations "fields" to build a partial record section,
  1638     "extend" to promote a fixed record to a record scheme, and
  1639     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  1640     declared as simp by default;
  1641   - shared operations ("more", "fields", etc.) now need to be always
  1642     qualified) --- potential INCOMPATIBILITY;
  1643   - removed "make_scheme" operations (use "make" with "extend") --
  1644     INCOMPATIBILITY;
  1645   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  1646   - provides cases/induct rules for use with corresponding Isar
  1647     methods (for concrete records, record schemes, concrete more
  1648     parts, and schematic more parts -- in that order);
  1649   - internal definitions directly based on a light-weight abstract
  1650     theory of product types over typedef rather than datatype;
  1651 
  1652 * HOL: generic code generator for generating executable ML code from
  1653 specifications; specific support for HOL constructs such as inductive
  1654 datatypes and sets, as well as recursive functions; can be invoked
  1655 via 'generate_code' theory section;
  1656 
  1657 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  1658 
  1659 * HOL: consolidated and renamed several theories.  In particular:
  1660         Ord.thy has been absorbed into HOL.thy
  1661         String.thy has been absorbed into List.thy
  1662 
  1663 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  1664 (beware of argument permutation!);
  1665 
  1666 * HOL: linorder_less_split superseded by linorder_cases;
  1667 
  1668 * HOL/List: "nodups" renamed to "distinct";
  1669 
  1670 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  1671 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  1672   - Ex_def has changed, now need to use some_eq_ex
  1673 
  1674 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  1675 in this (rare) case use:
  1676 
  1677   delSWrapper "split_all_tac"
  1678   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  1679 
  1680 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  1681 MAY FAIL;
  1682 
  1683 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  1684 Isabelle's type classes, ^ on functions and relations has too general
  1685 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  1686 necessary to attach explicit type constraints;
  1687 
  1688 * HOL/Relation: the prefix name of the infix "O" has been changed from
  1689 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  1690 renamed accordingly (eg "compI" -> "rel_compI").
  1691 
  1692 * HOL: syntax translations now work properly with numerals and records
  1693 expressions;
  1694 
  1695 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  1696 of "lam" -- INCOMPATIBILITY;
  1697 
  1698 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  1699 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  1700 renamed "Product_Type.unit";
  1701 
  1702 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  1703 
  1704 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  1705 the "cases" method);
  1706 
  1707 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  1708 Florian Kammller);
  1709 
  1710 * HOL/IMP: updated and converted to new-style theory format; several
  1711 parts turned into readable document, with proper Isar proof texts and
  1712 some explanations (by Gerwin Klein);
  1713 
  1714 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  1715 
  1716 * HOL-Hyperreal is now a logic image;
  1717 
  1718 
  1719 *** HOLCF ***
  1720 
  1721 * Isar: consts/constdefs supports mixfix syntax for continuous
  1722 operations;
  1723 
  1724 * Isar: domain package adapted to new-style theory format, e.g. see
  1725 HOLCF/ex/Dnat.thy;
  1726 
  1727 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  1728 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  1729 lift.induct_tac, always use UU instead of Undef;
  1730 
  1731 * HOLCF/IMP: updated and converted to new-style theory;
  1732 
  1733 
  1734 *** ZF ***
  1735 
  1736 * Isar: proper integration of logic-specific tools and packages,
  1737 including theory commands '(co)inductive', '(co)datatype',
  1738 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  1739 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  1740 
  1741 * theory Main no longer includes AC; for the Axiom of Choice, base
  1742 your theory on Main_ZFC;
  1743 
  1744 * the integer library now covers quotients and remainders, with many
  1745 laws relating division to addition, multiplication, etc.;
  1746 
  1747 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  1748 typeless version of the formalism;
  1749 
  1750 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  1751 format;
  1752 
  1753 * ZF/Induct: new directory for examples of inductive definitions,
  1754 including theory Multiset for multiset orderings; converted to
  1755 new-style theory format;
  1756 
  1757 * ZF: many new theorems about lists, ordinals, etc.;
  1758 
  1759 
  1760 *** General ***
  1761 
  1762 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  1763 variable proof controls level of detail: 0 = no proofs (only oracle
  1764 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  1765 also ref manual for further ML interfaces;
  1766 
  1767 * Pure/axclass: removed obsolete ML interface
  1768 goal_subclass/goal_arity;
  1769 
  1770 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  1771 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  1772 separate tokens, so expressions involving minus need to be spaced
  1773 properly;
  1774 
  1775 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  1776 rather than "infixl" or "infixr";
  1777 
  1778 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  1779 sort constraint specifications in type inference; e.g. "x::_::foo"
  1780 ensures that the type of "x" is of sort "foo" (but not necessarily a
  1781 type variable);
  1782 
  1783 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  1784 control output of nested => (types); the default behavior is
  1785 "type_brackets";
  1786 
  1787 * Pure/syntax: builtin parse translation for "_constify" turns valued
  1788 tokens into AST constants;
  1789 
  1790 * Pure/syntax: prefer later declarations of translations and print
  1791 translation functions; potential INCOMPATIBILITY: need to reverse
  1792 multiple declarations for same syntax element constant;
  1793 
  1794 * Pure/show_hyps reset by default (in accordance to existing Isar
  1795 practice);
  1796 
  1797 * Provers/classical: renamed addaltern to addafter, addSaltern to
  1798 addSafter;
  1799 
  1800 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  1801 as well;
  1802 
  1803 * system: tested support for MacOS X; should be able to get Isabelle +
  1804 Proof General to work in a plain Terminal after installing Poly/ML
  1805 (e.g. from the Isabelle distribution area) and GNU bash alone
  1806 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  1807 support requires further installations, e.g. from
  1808 http://fink.sourceforge.net/);
  1809 
  1810 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  1811 
  1812 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  1813 of 40 MB), cf. ML_OPTIONS;
  1814 
  1815 * system: Proof General keywords specification is now part of the
  1816 Isabelle distribution (see etc/isar-keywords.el);
  1817 
  1818 * system: support for persistent Proof General sessions (refrain from
  1819 outdating all loaded theories on startup); user may create writable
  1820 logic images like this: ``isabelle -q HOL Test'';
  1821 
  1822 * system: smart selection of Isabelle process versus Isabelle
  1823 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  1824 run both "isabelle" and "Isabelle" even if file names are badly
  1825 damaged (executable inspects the case of the first letter of its own
  1826 name); added separate "isabelle-process" and "isabelle-interface";
  1827 
  1828 * system: refrain from any attempt at filtering input streams; no
  1829 longer support ``8bit'' encoding of old isabelle font, instead proper
  1830 iso-latin characters may now be used; the related isatools
  1831 "symbolinput" and "nonascii" have disappeared as well;
  1832 
  1833 * system: removed old "xterm" interface (the print modes "xterm" and
  1834 "xterm_color" are still available for direct use in a suitable
  1835 terminal);
  1836 
  1837 
  1838 
  1839 New in Isabelle99-2 (February 2001)
  1840 -----------------------------------
  1841 
  1842 *** Overview of INCOMPATIBILITIES ***
  1843 
  1844 * HOL: please note that theories in the Library and elsewhere often use the
  1845 new-style (Isar) format; to refer to their theorems in an ML script you must
  1846 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  1847 
  1848 * HOL: inductive package no longer splits induction rule aggressively,
  1849 but only as far as specified by the introductions given; the old
  1850 format may be recovered via ML function complete_split_rule or attribute
  1851 'split_rule (complete)';
  1852 
  1853 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  1854 gfp_Tarski to gfp_unfold;
  1855 
  1856 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  1857 
  1858 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  1859 relation); infix "^^" has been renamed "``"; infix "``" has been
  1860 renamed "`"; "univalent" has been renamed "single_valued";
  1861 
  1862 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  1863 operation;
  1864 
  1865 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  1866 
  1867 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  1868 
  1869 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  1870 consequence, it is no longer monotonic wrt. the local goal context
  1871 (which is now passed through the inductive cases);
  1872 
  1873 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  1874 \<gg> to \<ggreater>;
  1875 
  1876 
  1877 *** Document preparation ***
  1878 
  1879 * \isabellestyle{NAME} selects version of Isabelle output (currently
  1880 available: are "it" for near math-mode best-style output, "sl" for
  1881 slanted text style, and "tt" for plain type-writer; if no
  1882 \isabellestyle command is given, output is according to slanted
  1883 type-writer);
  1884 
  1885 * support sub/super scripts (for single symbols only), input syntax is
  1886 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  1887 
  1888 * some more standard symbols; see Appendix A of the system manual for
  1889 the complete list of symbols defined in isabellesym.sty;
  1890 
  1891 * improved isabelle style files; more abstract symbol implementation
  1892 (should now use \isamath{...} and \isatext{...} in custom symbol
  1893 definitions);
  1894 
  1895 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  1896 state; Note that presentation of goal states does not conform to
  1897 actual human-readable proof documents.  Please do not include goal
  1898 states into document output unless you really know what you are doing!
  1899 
  1900 * proper indentation of antiquoted output with proportional LaTeX
  1901 fonts;
  1902 
  1903 * no_document ML operator temporarily disables LaTeX document
  1904 generation;
  1905 
  1906 * isatool unsymbolize tunes sources for plain ASCII communication;
  1907 
  1908 
  1909 *** Isar ***
  1910 
  1911 * Pure: Isar now suffers initial goal statements to contain unbound
  1912 schematic variables (this does not conform to actual readable proof
  1913 documents, due to unpredictable outcome and non-compositional proof
  1914 checking); users who know what they are doing may use schematic goals
  1915 for Prolog-style synthesis of proven results;
  1916 
  1917 * Pure: assumption method (an implicit finishing) now handles actual
  1918 rules as well;
  1919 
  1920 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  1921 initial goal, declare "that" only as Pure intro (only for single
  1922 steps); the "that" rule assumption may now be involved in implicit
  1923 finishing, thus ".." becomes a feasible for trivial obtains;
  1924 
  1925 * Pure: default proof step now includes 'intro_classes'; thus trivial
  1926 instance proofs may be performed by "..";
  1927 
  1928 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  1929 statements as well;
  1930 
  1931 * Pure: more robust selection of calculational rules;
  1932 
  1933 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  1934 rule (as well as the assumption rule);
  1935 
  1936 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  1937 lemmas, using the graph browser tool;
  1938 
  1939 * Pure: predict failure of "show" in interactive mode;
  1940 
  1941 * Pure: 'thms_containing' now takes actual terms as arguments;
  1942 
  1943 * HOL: improved method 'induct' --- now handles non-atomic goals
  1944 (potential INCOMPATIBILITY); tuned error handling;
  1945 
  1946 * HOL: cases and induct rules now provide explicit hints about the
  1947 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  1948 any remaining facts are inserted into the goal verbatim;
  1949 
  1950 * HOL: local contexts (aka cases) may now contain term bindings as
  1951 well; the 'cases' and 'induct' methods new provide a ?case binding for
  1952 the result to be shown in each case;
  1953 
  1954 * HOL: added 'recdef_tc' command;
  1955 
  1956 * isatool convert assists in eliminating legacy ML scripts;
  1957 
  1958 
  1959 *** HOL ***
  1960 
  1961 * HOL/Library: a collection of generic theories to be used together
  1962 with main HOL; the theory loader path already includes this directory
  1963 by default; the following existing theories have been moved here:
  1964 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  1965 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  1966 
  1967 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  1968 modelling and verification task performed in Isabelle/HOL +
  1969 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  1970 
  1971 * HOL/Algebra: special summation operator SUM no longer exists, it has
  1972 been replaced by setsum; infix 'assoc' now has priority 50 (like
  1973 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  1974 'domain', this makes the theory consistent with mathematical
  1975 literature;
  1976 
  1977 * HOL basics: added overloaded operations "inverse" and "divide"
  1978 (infix "/"), syntax for generic "abs" operation, generic summation
  1979 operator \<Sum>;
  1980 
  1981 * HOL/typedef: simplified package, provide more useful rules (see also
  1982 HOL/subset.thy);
  1983 
  1984 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  1985 now expressed as a proper nested rule (old-style tactic scripts may
  1986 require atomize_strip_tac to cope with non-atomic premises);
  1987 
  1988 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  1989 to "split_conv" (old name still available for compatibility);
  1990 
  1991 * HOL: improved concrete syntax for strings (e.g. allows translation
  1992 rules with string literals);
  1993 
  1994 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  1995  and Fleuriot's mechanization of analysis, including the transcendental
  1996  functions for the reals;
  1997 
  1998 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  1999 
  2000 
  2001 *** CTT ***
  2002 
  2003 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  2004 "lam" is displayed as TWO lambda-symbols
  2005 
  2006 * CTT: theory Main now available, containing everything (that is, Bool
  2007 and Arith);
  2008 
  2009 
  2010 *** General ***
  2011 
  2012 * Pure: the Simplifier has been implemented properly as a derived rule
  2013 outside of the actual kernel (at last!); the overall performance
  2014 penalty in practical applications is about 50%, while reliability of
  2015 the Isabelle inference kernel has been greatly improved;
  2016 
  2017 * print modes "brackets" and "no_brackets" control output of nested =>
  2018 (types) and ==> (props); the default behaviour is "brackets";
  2019 
  2020 * Provers: fast_tac (and friends) now handle actual object-logic rules
  2021 as assumptions as well;
  2022 
  2023 * system: support Poly/ML 4.0;
  2024 
  2025 * system: isatool install handles KDE version 1 or 2;
  2026 
  2027 
  2028 
  2029 New in Isabelle99-1 (October 2000)
  2030 ----------------------------------
  2031 
  2032 *** Overview of INCOMPATIBILITIES ***
  2033 
  2034 * HOL: simplification of natural numbers is much changed; to partly
  2035 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  2036 issue the following ML commands:
  2037 
  2038   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  2039   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  2040 
  2041 * HOL: simplification no longer dives into case-expressions; this is
  2042 controlled by "t.weak_case_cong" for each datatype t;
  2043 
  2044 * HOL: nat_less_induct renamed to less_induct;
  2045 
  2046 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  2047 fixsome to patch .thy and .ML sources automatically;
  2048 
  2049   select_equality  -> some_equality
  2050   select_eq_Ex     -> some_eq_ex
  2051   selectI2EX       -> someI2_ex
  2052   selectI2         -> someI2
  2053   selectI          -> someI
  2054   select1_equality -> some1_equality
  2055   Eps_sym_eq       -> some_sym_eq_trivial
  2056   Eps_eq           -> some_eq_trivial
  2057 
  2058 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  2059 
  2060 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  2061 instead);
  2062 
  2063 * HOL: the recursion equations generated by 'recdef' are now called
  2064 f.simps instead of f.rules;
  2065 
  2066 * HOL: qed_spec_mp now also handles bounded ALL as well;
  2067 
  2068 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  2069 sometimes be needed;
  2070 
  2071 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  2072 
  2073 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  2074 
  2075 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  2076 product is now "<*>" instead of "Times"; the lexicographic product is
  2077 now "<*lex*>" instead of "**";
  2078 
  2079 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  2080 of main HOL, but was unused); better use HOL's datatype package;
  2081 
  2082 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  2083 the old syntax may be recovered as follows:
  2084 
  2085   syntax (symbols)
  2086     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  2087       (infixl "\\<oplus>" 100)
  2088 
  2089 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  2090 
  2091 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  2092 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  2093 internally;
  2094 
  2095 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  2096 changed from A/r to A//r;
  2097 
  2098 * ZF: new treatment of arithmetic (nat & int) may break some old
  2099 proofs;
  2100 
  2101 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  2102 rulify -> rule_format, elimify -> elim_format, ...);
  2103 
  2104 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2105 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  2106 should have to change intro!! to intro? only); replaced "delrule" by
  2107 "rule del";
  2108 
  2109 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  2110 
  2111 * Provers: strengthened force_tac by using new first_best_tac;
  2112 
  2113 * LaTeX document preparation: several changes of isabelle.sty (see
  2114 lib/texinputs);
  2115 
  2116 
  2117 *** Document preparation ***
  2118 
  2119 * formal comments (text blocks etc.) in new-style theories may now
  2120 contain antiquotations of thm/prop/term/typ/text to be presented
  2121 according to latex print mode; concrete syntax is like this:
  2122 @{term[show_types] "f(x) = a + x"};
  2123 
  2124 * isatool mkdir provides easy setup of Isabelle session directories,
  2125 including proper document sources;
  2126 
  2127 * generated LaTeX sources are now deleted after successful run
  2128 (isatool document -c); may retain a copy somewhere else via -D option
  2129 of isatool usedir;
  2130 
  2131 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  2132 style files, achieving self-contained LaTeX sources and simplifying
  2133 LaTeX debugging;
  2134 
  2135 * old-style theories now produce (crude) LaTeX output as well;
  2136 
  2137 * browser info session directories are now self-contained (may be put
  2138 on WWW server seperately); improved graphs of nested sessions; removed
  2139 graph for 'all sessions';
  2140 
  2141 * several improvements in isabelle style files; \isabellestyle{it}
  2142 produces fake math mode output; \isamarkupheader is now \section by
  2143 default; see lib/texinputs/isabelle.sty etc.;
  2144 
  2145 
  2146 *** Isar ***
  2147 
  2148 * Isar/Pure: local results and corresponding term bindings are now
  2149 subject to Hindley-Milner polymorphism (similar to ML); this
  2150 accommodates incremental type-inference very nicely;
  2151 
  2152 * Isar/Pure: new derived language element 'obtain' supports
  2153 generalized existence reasoning;
  2154 
  2155 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  2156 support accumulation of results, without applying any rules yet;
  2157 useful to collect intermediate results without explicit name
  2158 references, and for use with transitivity rules with more than 2
  2159 premises;
  2160 
  2161 * Isar/Pure: scalable support for case-analysis type proofs: new
  2162 'case' language element refers to local contexts symbolically, as
  2163 produced by certain proof methods; internally, case names are attached
  2164 to theorems as "tags";
  2165 
  2166 * Isar/Pure: theory command 'hide' removes declarations from
  2167 class/type/const name spaces;
  2168 
  2169 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  2170 indicate potential overloading;
  2171 
  2172 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  2173 
  2174 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  2175 "{a,b,c}" instead of {a,b,c};
  2176 
  2177 * Isar/Pure now provides its own version of intro/elim/dest
  2178 attributes; useful for building new logics, but beware of confusion
  2179 with the version in Provers/classical;
  2180 
  2181 * Isar/Pure: the local context of (non-atomic) goals is provided via
  2182 case name 'antecedent';
  2183 
  2184 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  2185 to the current context is now done automatically);
  2186 
  2187 * Isar/Pure: theory command 'method_setup' provides a simple interface
  2188 for definining proof methods in ML;
  2189 
  2190 * Isar/Provers: intro/elim/dest attributes changed; renamed
  2191 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  2192 most cases, one should have to change intro!! to intro? only);
  2193 replaced "delrule" by "rule del";
  2194 
  2195 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  2196 'symmetric' attribute (the latter supercedes [RS sym]);
  2197 
  2198 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  2199 method modifier); 'simp' method: 'only:' modifier removes loopers as
  2200 well (including splits);
  2201 
  2202 * Isar/Provers: Simplifier and Classical methods now support all kind
  2203 of modifiers used in the past, including 'cong', 'iff', etc.
  2204 
  2205 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  2206 of Simplifier and Classical reasoner);
  2207 
  2208 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  2209 now support named cases; major packages (inductive, datatype, primrec,
  2210 recdef) support case names and properly name parameters;
  2211 
  2212 * Isar/HOL: new transitivity rules for substitution in inequalities --
  2213 monotonicity conditions are extracted to be proven at end of
  2214 calculations;
  2215 
  2216 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  2217 method anyway;
  2218 
  2219 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  2220 split_if split_if_asm; datatype package provides theorems foo.splits =
  2221 foo.split foo.split_asm for each datatype;
  2222 
  2223 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  2224 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  2225 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  2226 use "(cases (simplified))" method in proper proof texts);
  2227 
  2228 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  2229 
  2230 * Isar: names of theorems etc. may be natural numbers as well;
  2231 
  2232 * Isar: 'pr' command: optional arguments for goals_limit and
  2233 ProofContext.prems_limit; no longer prints theory contexts, but only
  2234 proof states;
  2235 
  2236 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  2237 additional print modes to be specified; e.g. "pr(latex)" will print
  2238 proof state according to the Isabelle LaTeX style;
  2239 
  2240 * Isar: improved support for emulating tactic scripts, including proof
  2241 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  2242 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  2243 (for HOL datatypes);
  2244 
  2245 * Isar: simplified (more robust) goal selection of proof methods: 1st
  2246 goal, all goals, or explicit goal specifier (tactic emulation); thus
  2247 'proof method scripts' have to be in depth-first order;
  2248 
  2249 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  2250 
  2251 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  2252 should instead use individual commands for printing items
  2253 (print_commands, print_methods etc.);
  2254 
  2255 * Isar: added 'nothing' --- the empty list of theorems;
  2256 
  2257 
  2258 *** HOL ***
  2259 
  2260 * HOL/MicroJava: formalization of a fragment of Java, together with a
  2261 corresponding virtual machine and a specification of its bytecode
  2262 verifier and a lightweight bytecode verifier, including proofs of
  2263 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  2264 Cornelia Pusch (see also the homepage of project Bali at
  2265 http://isabelle.in.tum.de/Bali/);
  2266 
  2267 * HOL/Algebra: new theory of rings and univariate polynomials, by
  2268 Clemens Ballarin;
  2269 
  2270 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  2271 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  2272 Rasmussen;
  2273 
  2274 * HOL/Lattice: fundamental concepts of lattice theory and order
  2275 structures, including duals, properties of bounds versus algebraic
  2276 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  2277 Theorem for complete lattices etc.; may also serve as a demonstration
  2278 for abstract algebraic reasoning using axiomatic type classes, and
  2279 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  2280 
  2281 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  2282 von Oheimb;
  2283 
  2284 * HOL/IMPP: extension of IMP with local variables and mutually
  2285 recursive procedures, by David von Oheimb;
  2286 
  2287 * HOL/Lambda: converted into new-style theory and document;
  2288 
  2289 * HOL/ex/Multiquote: example of multiple nested quotations and
  2290 anti-quotations -- basically a generalized version of de-Bruijn
  2291 representation; very useful in avoiding lifting of operations;
  2292 
  2293 * HOL/record: added general record equality rule to simpset; fixed
  2294 select-update simplification procedure to handle extended records as
  2295 well; admit "r" as field name;
  2296 
  2297 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  2298 other numeric types and also as the identity of groups, rings, etc.;
  2299 
  2300 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  2301 Types nat and int belong to this axclass;
  2302 
  2303 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  2304    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  2305    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  2306   two terms #m*u and #n*u are replaced by #(m+n)*u
  2307     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  2308   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  2309     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  2310 
  2311 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  2312 powerful prover for predicate logic but knows nothing of clasets; see
  2313 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  2314 
  2315 * HOL: new version of "case_tac" subsumes both boolean case split and
  2316 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  2317 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  2318 
  2319 * HOL: simplification no longer dives into case-expressions: only the
  2320 selector expression is simplified, but not the remaining arms; to
  2321 enable full simplification of case-expressions for datatype t, you may
  2322 remove t.weak_case_cong from the simpset, either globally (Delcongs
  2323 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  2324 
  2325 * HOL/recdef: the recursion equations generated by 'recdef' for
  2326 function 'f' are now called f.simps instead of f.rules; if all
  2327 termination conditions are proved automatically, these simplification
  2328 rules are added to the simpset, as in primrec; rules may be named
  2329 individually as well, resulting in a separate list of theorems for
  2330 each equation;
  2331 
  2332 * HOL/While is a new theory that provides a while-combinator. It
  2333 permits the definition of tail-recursive functions without the
  2334 provision of a termination measure. The latter is necessary once the
  2335 invariant proof rule for while is applied.
  2336 
  2337 * HOL: new (overloaded) notation for the set of elements below/above
  2338 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  2339 
  2340 * HOL: theorems impI, allI, ballI bound as "strip";
  2341 
  2342 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  2343 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  2344 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  2345 
  2346 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  2347 
  2348 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  2349 main HOL, but was unused);
  2350 
  2351 * HOL: fewer consts declared as global (e.g. have to refer to
  2352 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  2353 
  2354 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  2355 in case of overlap with user translations (e.g. judgements over
  2356 tuples); (note that the underlying logical represenation is still
  2357 bogus);
  2358 
  2359 
  2360 *** ZF ***
  2361 
  2362 * ZF: simplification automatically cancels common terms in arithmetic
  2363 expressions over nat and int;
  2364 
  2365 * ZF: new treatment of nat to minimize type-checking: all operators
  2366 coerce their operands to a natural number using the function natify,
  2367 making the algebraic laws unconditional;
  2368 
  2369 * ZF: as above, for int: operators coerce their operands to an integer
  2370 using the function intify;
  2371 
  2372 * ZF: the integer library now contains many of the usual laws for the
  2373 orderings, including $<=, and monotonicity laws for $+ and $*;
  2374 
  2375 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  2376 simplification;
  2377 
  2378 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  2379 to the simplifier and classical reasoner simultaneously;
  2380 
  2381 
  2382 *** General ***
  2383 
  2384 * Provers: blast_tac now handles actual object-logic rules as
  2385 assumptions; note that auto_tac uses blast_tac internally as well;
  2386 
  2387 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  2388 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  2389 
  2390 * Provers: delrules now handles destruct rules as well (no longer need
  2391 explicit make_elim);
  2392 
  2393 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  2394   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2395 use instead the strong form,
  2396   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  2397 in HOL, FOL and ZF the function cla_make_elim will create such rules
  2398 from destruct-rules;
  2399 
  2400 * Provers: Simplifier.easy_setup provides a fast path to basic
  2401 Simplifier setup for new object-logics;
  2402 
  2403 * Pure: AST translation rules no longer require constant head on LHS;
  2404 
  2405 * Pure: improved name spaces: ambiguous output is qualified; support
  2406 for hiding of names;
  2407 
  2408 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  2409 XSYMBOL_HOME; no longer need to do manual configuration in most
  2410 situations;
  2411 
  2412 * system: compression of ML heaps images may now be controlled via -c
  2413 option of isabelle and isatool usedir (currently only observed by
  2414 Poly/ML);
  2415 
  2416 * system: isatool installfonts may handle X-Symbol fonts as well (very
  2417 useful for remote X11);
  2418 
  2419 * system: provide TAGS file for Isabelle sources;
  2420 
  2421 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  2422 order;
  2423 
  2424 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  2425 timing flag supersedes proof_timing and Toplevel.trace;
  2426 
  2427 * ML: new combinators |>> and |>>> for incremental transformations
  2428 with secondary results (e.g. certain theory extensions):
  2429 
  2430 * ML: PureThy.add_defs gets additional argument to indicate potential
  2431 overloading (usually false);
  2432 
  2433 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  2434 results;
  2435 
  2436 
  2437 
  2438 New in Isabelle99 (October 1999)
  2439 --------------------------------
  2440 
  2441 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2442 
  2443 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  2444 are no longer simplified.  (This allows the simplifier to unfold recursive
  2445 functional programs.)  To restore the old behaviour, declare
  2446 
  2447     Delcongs [if_weak_cong];
  2448 
  2449 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  2450 complement;
  2451 
  2452 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  2453 
  2454 * HOL/datatype: mutual_induct_tac no longer exists --
  2455   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  2456 
  2457 * HOL/typedef: fixed type inference for representing set; type
  2458 arguments now have to occur explicitly on the rhs as type constraints;
  2459 
  2460 * ZF: The con_defs part of an inductive definition may no longer refer
  2461 to constants declared in the same theory;
  2462 
  2463 * HOL, ZF: the function mk_cases, generated by the inductive
  2464 definition package, has lost an argument.  To simplify its result, it
  2465 uses the default simpset instead of a supplied list of theorems.
  2466 
  2467 * HOL/List: the constructors of type list are now Nil and Cons;
  2468 
  2469 * Simplifier: the type of the infix ML functions
  2470         setSSolver addSSolver setSolver addSolver
  2471 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  2472 for packaging solvers. A solver is created via
  2473         mk_solver: string -> (thm list -> int -> tactic) -> solver
  2474 where the string argument is only a comment.
  2475 
  2476 
  2477 *** Proof tools ***
  2478 
  2479 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  2480 decision procedure for linear arithmetic. Currently it is used for
  2481 types `nat', `int', and `real' in HOL (see below); it can, should and
  2482 will be instantiated for other types and logics as well.
  2483 
  2484 * The simplifier now accepts rewrite rules with flexible heads, eg
  2485      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  2486   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  2487   matching.
  2488 
  2489 
  2490 *** General ***
  2491 
  2492 * New Isabelle/Isar subsystem provides an alternative to traditional
  2493 tactical theorem proving; together with the ProofGeneral/isar user
  2494 interface it offers an interactive environment for developing human
  2495 readable proof documents (Isar == Intelligible semi-automated
  2496 reasoning); for further information see isatool doc isar-ref,
  2497 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  2498 
  2499 * improved and simplified presentation of theories: better HTML markup
  2500 (including colors), graph views in several sizes; isatool usedir now
  2501 provides a proper interface for user theories (via -P option); actual
  2502 document preparation based on (PDF)LaTeX is available as well (for
  2503 new-style theories only); see isatool doc system for more information;
  2504 
  2505 * native support for Proof General, both for classic Isabelle and
  2506 Isabelle/Isar;
  2507 
  2508 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  2509 using the graph browser tool;
  2510 
  2511 * Isabelle manuals now also available as PDF;
  2512 
  2513 * theory loader rewritten from scratch (may not be fully
  2514 bug-compatible); old loadpath variable has been replaced by show_path,
  2515 add_path, del_path, reset_path functions; new operations such as
  2516 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  2517 isatool doc ref);
  2518 
  2519 * improved isatool install: option -k creates KDE application icon,
  2520 option -p DIR installs standalone binaries;
  2521 
  2522 * added ML_PLATFORM setting (useful for cross-platform installations);
  2523 more robust handling of platform specific ML images for SML/NJ;
  2524 
  2525 * the settings environment is now statically scoped, i.e. it is never
  2526 created again in sub-processes invoked from isabelle, isatool, or
  2527 Isabelle;
  2528 
  2529 * path element specification '~~' refers to '$ISABELLE_HOME';
  2530 
  2531 * in locales, the "assumes" and "defines" parts may be omitted if
  2532 empty;
  2533 
  2534 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  2535 long arrows);
  2536 
  2537 * new print_mode "HTML";
  2538 
  2539 * new flag show_tags controls display of tags of theorems (which are
  2540 basically just comments that may be attached by some tools);
  2541 
  2542 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  2543 mode and goal output format:
  2544 
  2545 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  2546 244c244
  2547 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  2548 ---
  2549 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  2550 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  2551 181c181
  2552 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  2553 ---
  2554 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  2555 
  2556 * function bind_thms stores lists of theorems (cf. bind_thm);
  2557 
  2558 * new shorthand tactics ftac, eatac, datac, fatac;
  2559 
  2560 * qed (and friends) now accept "" as result name; in that case the
  2561 theorem is not stored, but proper checks and presentation of the
  2562 result still apply;
  2563 
  2564 * theorem database now also indexes constants "Trueprop", "all",
  2565 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  2566 
  2567 
  2568 *** HOL ***
  2569 
  2570 ** HOL arithmetic **
  2571 
  2572 * There are now decision procedures for linear arithmetic over nat and
  2573 int:
  2574 
  2575 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  2576 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  2577 are treated as atomic; subformulae not involving type `nat' or `int'
  2578 are ignored; quantified subformulae are ignored unless they are
  2579 positive universal or negative existential. The tactic has to be
  2580 invoked by hand and can be a little bit slow. In particular, the
  2581 running time is exponential in the number of occurrences of `min' and
  2582 `max', and `-' on `nat'.
  2583 
  2584 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  2585 (negated) (in)equalities among the premises and the conclusion into
  2586 account (i.e. no compound formulae) and does not know about `min' and
  2587 `max', and `-' on `nat'. It is fast and is used automatically by the
  2588 simplifier.
  2589 
  2590 NB: At the moment, these decision procedures do not cope with mixed
  2591 nat/int formulae where the two parts interact, such as `m < n ==>
  2592 int(m) < int(n)'.
  2593 
  2594 * HOL/Numeral provides a generic theory of numerals (encoded
  2595 efficiently as bit strings); setup for types nat/int/real is in place;
  2596 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  2597 int, existing theories and proof scripts may require a few additional
  2598 type constraints;
  2599 
  2600 * integer division and remainder can now be performed on constant
  2601 arguments;
  2602 
  2603 * many properties of integer multiplication, division and remainder
  2604 are now available;
  2605 
  2606 * An interface to the Stanford Validity Checker (SVC) is available through the
  2607 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  2608 are proved automatically.  SVC must be installed separately, and its results
  2609 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  2610 invocation of the underlying oracle).  For SVC see
  2611   http://verify.stanford.edu/SVC
  2612 
  2613 * IsaMakefile: the HOL-Real target now builds an actual image;
  2614 
  2615 
  2616 ** HOL misc **
  2617 
  2618 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  2619 (in Isabelle/Isar) -- by Gertrud Bauer;
  2620 
  2621 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  2622 analysis for assembly languages with subtypes;
  2623 
  2624 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  2625 -- avoids syntactic ambiguities and treats state, transition, and
  2626 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  2627 changed syntax and (many) tactics;
  2628 
  2629 * HOL/inductive: Now also handles more general introduction rules such
  2630   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  2631   theorems are now maintained within the theory (maintained via the
  2632   "mono" attribute);
  2633 
  2634 * HOL/datatype: Now also handles arbitrarily branching datatypes
  2635   (using function types) such as
  2636 
  2637   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  2638 
  2639 * HOL/record: record_simproc (part of the default simpset) takes care
  2640 of selectors applied to updated records; record_split_tac is no longer
  2641 part of the default claset; update_defs may now be removed from the
  2642 simpset in many cases; COMPATIBILITY: old behavior achieved by
  2643 
  2644   claset_ref () := claset() addSWrapper record_split_wrapper;
  2645   Delsimprocs [record_simproc]
  2646 
  2647 * HOL/typedef: fixed type inference for representing set; type
  2648 arguments now have to occur explicitly on the rhs as type constraints;
  2649 
  2650 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  2651 names rather than an ML expression;
  2652 
  2653 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  2654 supplied later.  Program schemes can be defined, such as
  2655     "While B C s = (if B s then While B C (C s) else s)"
  2656 where the well-founded relation can be chosen after B and C have been given.
  2657 
  2658 * HOL/List: the constructors of type list are now Nil and Cons;
  2659 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  2660 course, ML tools referring to List.list.op # etc. have to be adapted;
  2661 
  2662 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  2663 disabled by default; run isabelle with option -m HOL to get back to
  2664 the original Gordon/HOL-style output;
  2665 
  2666 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  2667 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  2668 
  2669 * HOL basic syntax simplified (more orthogonal): all variants of
  2670 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  2671 Eps operator is provided as well: "SOME x. P[x]";
  2672 
  2673 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  2674 
  2675 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  2676 thus available for user theories;
  2677 
  2678 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  2679 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  2680 time;
  2681 
  2682 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  2683 several times and then mp;
  2684 
  2685 
  2686 *** LK ***
  2687 
  2688 * the notation <<...>> is now available as a notation for sequences of
  2689 formulas;
  2690 
  2691 * the simplifier is now installed
  2692 
  2693 * the axiom system has been generalized (thanks to Soren Heilmann)
  2694 
  2695 * the classical reasoner now has a default rule database
  2696 
  2697 
  2698 *** ZF ***
  2699 
  2700 * new primrec section allows primitive recursive functions to be given
  2701 directly (as in HOL) over datatypes and the natural numbers;
  2702 
  2703 * new tactics induct_tac and exhaust_tac for induction (or case
  2704 analysis) over datatypes and the natural numbers;
  2705 
  2706 * the datatype declaration of type T now defines the recursor T_rec;
  2707 
  2708 * simplification automatically does freeness reasoning for datatype
  2709 constructors;
  2710 
  2711 * automatic type-inference, with AddTCs command to insert new
  2712 type-checking rules;
  2713 
  2714 * datatype introduction rules are now added as Safe Introduction rules
  2715 to the claset;
  2716 
  2717 * the syntax "if P then x else y" is now available in addition to
  2718 if(P,x,y);
  2719 
  2720 
  2721 *** Internal programming interfaces ***
  2722 
  2723 * tuned simplifier trace output; new flag debug_simp;
  2724 
  2725 * structures Vartab / Termtab (instances of TableFun) offer efficient
  2726 tables indexed by indexname_ord / term_ord (compatible with aconv);
  2727 
  2728 * AxClass.axclass_tac lost the theory argument;
  2729 
  2730 * tuned current_goals_markers semantics: begin / end goal avoids
  2731 printing empty lines;
  2732 
  2733 * removed prs and prs_fn hook, which was broken because it did not
  2734 include \n in its semantics, forcing writeln to add one
  2735 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  2736 string -> unit if you really want to output text without newline;
  2737 
  2738 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  2739 plain output, interface builders may have to enable 'isabelle_font'
  2740 mode to get Isabelle font glyphs as before;
  2741 
  2742 * refined token_translation interface; INCOMPATIBILITY: output length
  2743 now of type real instead of int;
  2744 
  2745 * theory loader actions may be traced via new ThyInfo.add_hook
  2746 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  2747 your own database of information attached to *whole* theories -- as
  2748 opposed to intra-theory data slots offered via TheoryDataFun;
  2749 
  2750 * proper handling of dangling sort hypotheses (at last!);
  2751 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  2752 extra sort hypotheses that can be witnessed from the type signature;
  2753 the force_strip_shyps flag is gone, any remaining shyps are simply
  2754 left in the theorem (with a warning issued by strip_shyps_warning);
  2755 
  2756 
  2757 
  2758 New in Isabelle98-1 (October 1998)
  2759 ----------------------------------
  2760 
  2761 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2762 
  2763 * several changes of automated proof tools;
  2764 
  2765 * HOL: major changes to the inductive and datatype packages, including
  2766 some minor incompatibilities of theory syntax;
  2767 
  2768 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  2769 called `inj_on';
  2770 
  2771 * HOL: removed duplicate thms in Arith:
  2772   less_imp_add_less  should be replaced by  trans_less_add1
  2773   le_imp_add_le      should be replaced by  trans_le_add1
  2774 
  2775 * HOL: unary minus is now overloaded (new type constraints may be
  2776 required);
  2777 
  2778 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  2779 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  2780 now taken as an integer constant.
  2781 
  2782 * Pure: ML function 'theory_of' renamed to 'theory';
  2783 
  2784 
  2785 *** Proof tools ***
  2786 
  2787 * Simplifier:
  2788   1. Asm_full_simp_tac is now more aggressive.
  2789      1. It will sometimes reorient premises if that increases their power to
  2790         simplify.
  2791      2. It does no longer proceed strictly from left to right but may also
  2792         rotate premises to achieve further simplification.
  2793      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  2794      old Asm_full_simp_tac in that it does not rotate premises.
  2795   2. The simplifier now knows a little bit about nat-arithmetic.
  2796 
  2797 * Classical reasoner: wrapper mechanism for the classical reasoner now
  2798 allows for selected deletion of wrappers, by introduction of names for
  2799 wrapper functionals.  This implies that addbefore, addSbefore,
  2800 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  2801 and that adding two tactics with the same name overwrites the first
  2802 one (emitting a warning).
  2803   type wrapper = (int -> tactic) -> (int -> tactic)
  2804   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  2805   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  2806   delWrapper, delSWrapper: claset *  string            -> claset
  2807   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  2808 
  2809 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  2810 semantics; addbefore now affects only the unsafe part of step_tac
  2811 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  2812 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  2813 by Force_tac;
  2814 
  2815 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  2816 compWrapper; added safe wrapper (and access functions for it);
  2817 
  2818 * HOL/split_all_tac is now much faster and fails if there is nothing
  2819 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  2820 and the names of the automatically generated variables have changed.
  2821 split_all_tac has moved within claset() from unsafe wrappers to safe
  2822 wrappers, which means that !!-bound variables are split much more
  2823 aggressively, and safe_tac and clarify_tac now split such variables.
  2824 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  2825 Note: the same holds for record_split_tac, which does the job of
  2826 split_all_tac for record fields.
  2827 
  2828 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  2829 permanently to the default simpset using Addsplits just like
  2830 Addsimps. They can be removed via Delsplits just like
  2831 Delsimps. Lower-case versions are also available.
  2832 
  2833 * HOL/Simplifier: The rule split_if is now part of the default
  2834 simpset. This means that the simplifier will eliminate all occurrences
  2835 of if-then-else in the conclusion of a goal. To prevent this, you can
  2836 either remove split_if completely from the default simpset by
  2837 `Delsplits [split_if]' or remove it in a specific call of the
  2838 simplifier using `... delsplits [split_if]'.  You can also add/delete
  2839 other case splitting rules to/from the default simpset: every datatype
  2840 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  2841 t is the name of the datatype).
  2842 
  2843 * Classical reasoner / Simplifier combination: new force_tac (and
  2844 derivatives Force_tac, force) combines rewriting and classical
  2845 reasoning (and whatever other tools) similarly to auto_tac, but is
  2846 aimed to solve the given subgoal completely.
  2847 
  2848 
  2849 *** General ***
  2850 
  2851 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  2852 and `goalw': the theory is no longer needed as an explicit argument -
  2853 the current theory context is used; assumptions are no longer returned
  2854 at the ML-level unless one of them starts with ==> or !!; it is
  2855 recommended to convert to these new commands using isatool fixgoal
  2856 (backup your sources first!);
  2857 
  2858 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  2859 the current theory context, and 'theory' to lookup stored theories;
  2860 
  2861 * new theory section 'locale' for declaring constants, assumptions and
  2862 definitions that have local scope;
  2863 
  2864 * new theory section 'nonterminals' for purely syntactic types;
  2865 
  2866 * new theory section 'setup' for generic ML setup functions
  2867 (e.g. package initialization);
  2868 
  2869 * the distribution now includes Isabelle icons: see
  2870 lib/logo/isabelle-{small,tiny}.xpm;
  2871 
  2872 * isatool install - install binaries with absolute references to
  2873 ISABELLE_HOME/bin;
  2874 
  2875 * isatool logo -- create instances of the Isabelle logo (as EPS);
  2876 
  2877 * print mode 'emacs' reserved for Isamode;
  2878 
  2879 * support multiple print (ast) translations per constant name;
  2880 
  2881 * theorems involving oracles are now printed with a suffixed [!];
  2882 
  2883 
  2884 *** HOL ***
  2885 
  2886 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  2887 
  2888 * HOL/inductive package reorganized and improved: now supports mutual
  2889 definitions such as
  2890 
  2891   inductive EVEN ODD
  2892     intrs
  2893       null "0 : EVEN"
  2894       oddI "n : EVEN ==> Suc n : ODD"
  2895       evenI "n : ODD ==> Suc n : EVEN"
  2896 
  2897 new theorem list "elims" contains an elimination rule for each of the
  2898 recursive sets; inductive definitions now handle disjunctive premises
  2899 correctly (also ZF);
  2900 
  2901 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  2902 "mutual_induct" no longer exists - the induction rule is always
  2903 contained in "induct";
  2904 
  2905 
  2906 * HOL/datatype package re-implemented and greatly improved: now
  2907 supports mutually recursive datatypes such as
  2908 
  2909   datatype
  2910     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  2911             | SUM ('a aexp) ('a aexp)
  2912             | DIFF ('a aexp) ('a aexp)
  2913             | NUM 'a
  2914   and
  2915     'a bexp = LESS ('a aexp) ('a aexp)
  2916             | AND ('a bexp) ('a bexp)
  2917             | OR ('a bexp) ('a bexp)
  2918 
  2919 as well as indirectly recursive datatypes such as
  2920 
  2921   datatype
  2922     ('a, 'b) term = Var 'a
  2923                   | App 'b ((('a, 'b) term) list)
  2924 
  2925 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  2926 induction on mutually / indirectly recursive datatypes.
  2927 
  2928 Primrec equations are now stored in theory and can be accessed via
  2929 <function_name>.simps.
  2930 
  2931 INCOMPATIBILITIES:
  2932 
  2933   - Theories using datatypes must now have theory Datatype as an
  2934     ancestor.
  2935   - The specific <typename>.induct_tac no longer exists - use the
  2936     generic induct_tac instead.
  2937   - natE has been renamed to nat.exhaust - use exhaust_tac
  2938     instead of res_inst_tac ... natE. Note that the variable
  2939     names in nat.exhaust differ from the names in natE, this
  2940     may cause some "fragile" proofs to fail.
  2941   - The theorems split_<typename>_case and split_<typename>_case_asm
  2942     have been renamed to <typename>.split and <typename>.split_asm.
  2943   - Since default sorts of type variables are now handled correctly,
  2944     some datatype definitions may have to be annotated with explicit
  2945     sort constraints.
  2946   - Primrec definitions no longer require function name and type
  2947     of recursive argument.
  2948 
  2949 Consider using isatool fixdatatype to adapt your theories and proof
  2950 scripts to the new package (backup your sources first!).
  2951 
  2952 
  2953 * HOL/record package: considerably improved implementation; now
  2954 includes concrete syntax for record types, terms, updates; theorems
  2955 for surjective pairing and splitting !!-bound record variables; proof
  2956 support is as follows:
  2957 
  2958   1) standard conversions (selectors or updates applied to record
  2959 constructor terms) are part of the standard simpset;
  2960 
  2961   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  2962 made part of standard simpset and claset via addIffs;
  2963 
  2964   3) a tactic for record field splitting (record_split_tac) is part of
  2965 the standard claset (addSWrapper);
  2966 
  2967 To get a better idea about these rules you may retrieve them via
  2968 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  2969 the name of your record type.
  2970 
  2971 The split tactic 3) conceptually simplifies by the following rule:
  2972 
  2973   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  2974 
  2975 Thus any record variable that is bound by meta-all will automatically
  2976 blow up into some record constructor term, consequently the
  2977 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  2978 solve record problems automatically.
  2979 
  2980 
  2981 * reorganized the main HOL image: HOL/Integ and String loaded by
  2982 default; theory Main includes everything;
  2983 
  2984 * automatic simplification of integer sums and comparisons, using cancellation;
  2985 
  2986 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  2987 
  2988 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  2989 
  2990 * many new identities for unions, intersections, set difference, etc.;
  2991 
  2992 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  2993 called split_if, split_split, split_sum_case and split_nat_case (to go
  2994 with add/delsplits);
  2995 
  2996 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  2997 (?x::unit) = (); this is made part of the default simpset, which COULD
  2998 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  2999 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  3000 unit_abs_eta_conv is added in order to counter the effect of
  3001 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  3002 %u.f();
  3003 
  3004 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  3005 makes more sense);
  3006 
  3007 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3008   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3009   disjointness reasoning but breaking a few old proofs.
  3010 
  3011 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  3012 to 'converse' from 'inverse' (for compatibility with ZF and some
  3013 literature);
  3014 
  3015 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  3016 the well-founded relation;
  3017 
  3018 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  3019     Compl A.  The "Compl" syntax remains available as input syntax for this
  3020     release ONLY.
  3021 
  3022 * HOL/Update: new theory of function updates:
  3023     f(a:=b) == %x. if x=a then b else f x
  3024 may also be iterated as in f(a:=b,c:=d,...);
  3025 
  3026 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  3027 
  3028 * HOL/List:
  3029   - new function list_update written xs[i:=v] that updates the i-th
  3030     list position. May also be iterated as in xs[i:=a,j:=b,...].
  3031   - new function `upt' written [i..j(] which generates the list
  3032     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  3033     bound write [i..j], which is a shorthand for [i..j+1(].
  3034   - new lexicographic orderings and corresponding wellfoundedness theorems.
  3035 
  3036 * HOL/Arith:
  3037   - removed 'pred' (predecessor) function;
  3038   - generalized some theorems about n-1;
  3039   - many new laws about "div" and "mod";
  3040   - new laws about greatest common divisors (see theory ex/Primes);
  3041 
  3042 * HOL/Relation: renamed the relational operator r^-1 "converse"
  3043 instead of "inverse";
  3044 
  3045 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  3046   of the multiset ordering;
  3047 
  3048 * directory HOL/Real: a construction of the reals using Dedekind cuts
  3049   (not included by default);
  3050 
  3051 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  3052 
  3053 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  3054   programs, i.e. different program variables may have different types.
  3055 
  3056 * calling (stac rew i) now fails if "rew" has no effect on the goal
  3057   [previously, this check worked only if the rewrite rule was unconditional]
  3058   Now rew can involve either definitions or equalities (either == or =).
  3059 
  3060 
  3061 *** ZF ***
  3062 
  3063 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  3064   only the theorems proved on ZF.ML;
  3065 
  3066 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  3067   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  3068   disjointness reasoning but breaking a few old proofs.
  3069 
  3070 * ZF/Update: new theory of function updates
  3071     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  3072   may also be iterated as in f(a:=b,c:=d,...);
  3073 
  3074 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  3075 
  3076 * calling (stac rew i) now fails if "rew" has no effect on the goal
  3077   [previously, this check worked only if the rewrite rule was unconditional]
  3078   Now rew can involve either definitions or equalities (either == or =).
  3079 
  3080 * case_tac provided for compatibility with HOL
  3081     (like the old excluded_middle_tac, but with subgoals swapped)
  3082 
  3083 
  3084 *** Internal programming interfaces ***
  3085 
  3086 * Pure: several new basic modules made available for general use, see
  3087 also src/Pure/README;
  3088 
  3089 * improved the theory data mechanism to support encapsulation (data
  3090 kind name replaced by private Object.kind, acting as authorization
  3091 key); new type-safe user interface via functor TheoryDataFun; generic
  3092 print_data function becomes basically useless;
  3093 
  3094 * removed global_names compatibility flag -- all theory declarations
  3095 are qualified by default;
  3096 
  3097 * module Pure/Syntax now offers quote / antiquote translation
  3098 functions (useful for Hoare logic etc. with implicit dependencies);
  3099 see HOL/ex/Antiquote for an example use;
  3100 
  3101 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  3102 cterm -> thm;
  3103 
  3104 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  3105 subgoal;
  3106 
  3107 * Display.print_goals function moved to Locale.print_goals;
  3108 
  3109 * standard print function for goals supports current_goals_markers
  3110 variable for marking begin of proof, end of proof, start of goal; the
  3111 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  3112 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  3113 for example;
  3114 
  3115 
  3116 
  3117 New in Isabelle98 (January 1998)
  3118 --------------------------------
  3119 
  3120 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3121 
  3122 * changed lexical syntax of terms / types: dots made part of long
  3123 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  3124 
  3125 * simpset (and claset) reference variable replaced by functions
  3126 simpset / simpset_ref;
  3127 
  3128 * no longer supports theory aliases (via merge) and non-trivial
  3129 implicit merge of thms' signatures;
  3130 
  3131 * most internal names of constants changed due to qualified names;
  3132 
  3133 * changed Pure/Sequence interface (see Pure/seq.ML);
  3134 
  3135 
  3136 *** General Changes ***
  3137 
  3138 * hierachically structured name spaces (for consts, types, axms, thms
  3139 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  3140 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  3141 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  3142 long_names for fully qualified output names; NOTE: ML programs
  3143 (special tactics, packages etc.) referring to internal names may have
  3144 to be adapted to cope with fully qualified names; in case of severe
  3145 backward campatibility problems try setting 'global_names' at compile
  3146 time to have enrything declared within a flat name space; one may also
  3147 fine tune name declarations in theories via the 'global' and 'local'
  3148 section;
  3149 
  3150 * reimplemented the implicit simpset and claset using the new anytype
  3151 data filed in signatures; references simpset:simpset ref etc. are
  3152 replaced by functions simpset:unit->simpset and
  3153 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  3154 to patch your ML files accordingly;
  3155 
  3156 * HTML output now includes theory graph data for display with Java
  3157 applet or isatool browser; data generated automatically via isatool
  3158 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  3159 
  3160 * defs may now be conditional; improved rewrite_goals_tac to handle
  3161 conditional equations;
  3162 
  3163 * defs now admits additional type arguments, using TYPE('a) syntax;
  3164 
  3165 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  3166 creates a new theory node; implicit merge of thms' signatures is
  3167 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  3168 transfer:theory->thm->thm in (rare) cases;
  3169 
  3170 * improved handling of draft signatures / theories; draft thms (and
  3171 ctyps, cterms) are automatically promoted to real ones;
  3172 
  3173 * slightly changed interfaces for oracles: admit many per theory, named
  3174 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  3175 
  3176 * print_goals: optional output of const types (set show_consts and
  3177 show_types);
  3178 
  3179 * improved output of warnings (###) and errors (***);
  3180 
  3181 * subgoal_tac displays a warning if the new subgoal has type variables;
  3182 
  3183 * removed old README and Makefiles;
  3184 
  3185 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  3186 
  3187 * removed obsolete init_pps and init_database;
  3188 
  3189 * deleted the obsolete tactical STATE, which was declared by
  3190     fun STATE tacfun st = tacfun st st;
  3191 
  3192 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  3193 (which abbreviates $HOME);
  3194 
  3195 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  3196 use isatool fixseq to adapt your ML programs (this works for fully
  3197 qualified references to the Sequence structure only!);
  3198 
  3199 * use_thy no longer requires writable current directory; it always
  3200 reloads .ML *and* .thy file, if either one is out of date;
  3201 
  3202 
  3203 *** Classical Reasoner ***
  3204 
  3205 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  3206 tactics that use classical reasoning to simplify a subgoal without
  3207 splitting it into several subgoals;
  3208 
  3209 * Safe_tac: like safe_tac but uses the default claset;
  3210 
  3211 
  3212 *** Simplifier ***
  3213 
  3214 * added simplification meta rules:
  3215     (asm_)(full_)simplify: simpset -> thm -> thm;
  3216 
  3217 * simplifier.ML no longer part of Pure -- has to be loaded by object
  3218 logics (again);
  3219 
  3220 * added prems argument to simplification procedures;
  3221 
  3222 * HOL, FOL, ZF: added infix function `addsplits':
  3223   instead of `<simpset> setloop (split_tac <thms>)'
  3224   you can simply write `<simpset> addsplits <thms>'
  3225 
  3226 
  3227 *** Syntax ***
  3228 
  3229 * TYPE('a) syntax for type reflection terms;
  3230 
  3231 * no longer handles consts with name "" -- declare as 'syntax' instead;
  3232 
  3233 * pretty printer: changed order of mixfix annotation preference (again!);
  3234 
  3235 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  3236 
  3237 
  3238 *** HOL ***
  3239 
  3240 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3241   with `addloop' of the simplifier to faciliate case splitting in premises.
  3242 
  3243 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  3244 
  3245 * HOL/Auth: new protocol proofs including some for the Internet
  3246   protocol TLS;
  3247 
  3248 * HOL/Map: new theory of `maps' a la VDM;
  3249 
  3250 * HOL/simplifier: simplification procedures nat_cancel_sums for
  3251 cancelling out common nat summands from =, <, <= (in)equalities, or
  3252 differences; simplification procedures nat_cancel_factor for
  3253 cancelling common factor from =, <, <= (in)equalities over natural
  3254 sums; nat_cancel contains both kinds of procedures, it is installed by
  3255 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  3256 
  3257 * HOL/simplifier: terms of the form
  3258   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  3259   are rewritten to
  3260   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  3261   and those of the form
  3262   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  3263   are rewritten to
  3264   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  3265 
  3266 * HOL/datatype
  3267   Each datatype `t' now comes with a theorem `split_t_case' of the form
  3268 
  3269   P(t_case f1 ... fn x) =
  3270      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  3271         ...
  3272        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  3273      )
  3274 
  3275   and a theorem `split_t_case_asm' of the form
  3276 
  3277   P(t_case f1 ... fn x) =
  3278     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  3279         ...
  3280        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  3281      )
  3282   which can be added to a simpset via `addsplits'. The existing theorems
  3283   expand_list_case and expand_option_case have been renamed to
  3284   split_list_case and split_option_case.
  3285 
  3286 * HOL/Arithmetic:
  3287   - `pred n' is automatically converted to `n-1'.
  3288     Users are strongly encouraged not to use `pred' any longer,
  3289     because it will disappear altogether at some point.
  3290   - Users are strongly encouraged to write "0 < n" rather than
  3291     "n ~= 0". Theorems and proof tools have been modified towards this
  3292     `standard'.
  3293 
  3294 * HOL/Lists:
  3295   the function "set_of_list" has been renamed "set" (and its theorems too);
  3296   the function "nth" now takes its arguments in the reverse order and
  3297   has acquired the infix notation "!" as in "xs!n".
  3298 
  3299 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  3300 
  3301 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  3302   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  3303 
  3304 * HOL/record: extensible records with schematic structural subtyping
  3305 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  3306 still lacks various theorems and concrete record syntax;
  3307 
  3308 
  3309 *** HOLCF ***
  3310 
  3311 * removed "axioms" and "generated by" sections;
  3312 
  3313 * replaced "ops" section by extended "consts" section, which is capable of
  3314   handling the continuous function space "->" directly;
  3315 
  3316 * domain package:
  3317   . proves theorems immediately and stores them in the theory,
  3318   . creates hierachical name space,
  3319   . now uses normal mixfix annotations (instead of cinfix...),
  3320   . minor changes to some names and values (for consistency),
  3321   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  3322   . separator between mutual domain defs: changed "," to "and",
  3323   . improved handling of sort constraints;  now they have to
  3324     appear on the left-hand side of the equations only;
  3325 
  3326 * fixed LAM <x,y,zs>.b syntax;
  3327 
  3328 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  3329 adm (%x. P (t x)), where P is chainfinite and t continuous;
  3330 
  3331 
  3332 *** FOL and ZF ***
  3333 
  3334 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  3335   with `addloop' of the simplifier to faciliate case splitting in premises.
  3336 
  3337 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  3338 in HOL, they strip ALL and --> from proved theorems;
  3339 
  3340 
  3341 
  3342 New in Isabelle94-8 (May 1997)
  3343 ------------------------------
  3344 
  3345 *** General Changes ***
  3346 
  3347 * new utilities to build / run / maintain Isabelle etc. (in parts
  3348 still somewhat experimental); old Makefiles etc. still functional;
  3349 
  3350 * new 'Isabelle System Manual';
  3351 
  3352 * INSTALL text, together with ./configure and ./build scripts;
  3353 
  3354 * reimplemented type inference for greater efficiency, better error
  3355 messages and clean internal interface;
  3356 
  3357 * prlim command for dealing with lots of subgoals (an easier way of
  3358 setting goals_limit);
  3359 
  3360 
  3361 *** Syntax ***
  3362 
  3363 * supports alternative (named) syntax tables (parser and pretty
  3364 printer); internal interface is provided by add_modesyntax(_i);
  3365 
  3366 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  3367 be used in conjunction with the Isabelle symbol font; uses the
  3368 "symbols" syntax table;
  3369 
  3370 * added token_translation interface (may translate name tokens in
  3371 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  3372 the current print_mode); IMPORTANT: user print translation functions
  3373 are responsible for marking newly introduced bounds
  3374 (Syntax.mark_boundT);
  3375 
  3376 * token translations for modes "xterm" and "xterm_color" that display
  3377 names in bold, underline etc. or colors (which requires a color
  3378 version of xterm);
  3379 
  3380 * infixes may now be declared with names independent of their syntax;
  3381 
  3382 * added typed_print_translation (like print_translation, but may
  3383 access type of constant);
  3384 
  3385 
  3386 *** Classical Reasoner ***
  3387 
  3388 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  3389 some limitations.  Blast_tac...
  3390   + ignores addss, addbefore, addafter; this restriction is intrinsic
  3391   + ignores elimination rules that don't have the correct format
  3392         (the conclusion MUST be a formula variable)
  3393   + ignores types, which can make HOL proofs fail
  3394   + rules must not require higher-order unification, e.g. apply_type in ZF
  3395     [message "Function Var's argument not a bound variable" relates to this]
  3396   + its proof strategy is more general but can actually be slower
  3397 
  3398 * substitution with equality assumptions no longer permutes other
  3399 assumptions;
  3400 
  3401 * minor changes in semantics of addafter (now called addaltern); renamed
  3402 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  3403 (and access functions for it);
  3404 
  3405 * improved combination of classical reasoner and simplifier:
  3406   + functions for handling clasimpsets
  3407   + improvement of addss: now the simplifier is called _after_ the
  3408     safe steps.
  3409   + safe variant of addss called addSss: uses safe simplifications
  3410     _during_ the safe steps. It is more complete as it allows multiple
  3411     instantiations of unknowns (e.g. with slow_tac).
  3412 
  3413 *** Simplifier ***
  3414 
  3415 * added interface for simplification procedures (functions that
  3416 produce *proven* rewrite rules on the fly, depending on current
  3417 redex);
  3418 
  3419 * ordering on terms as parameter (used for ordered rewriting);
  3420 
  3421 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  3422 
  3423 * the solver is now split into a safe and an unsafe part.
  3424 This should be invisible for the normal user, except that the
  3425 functions setsolver and addsolver have been renamed to setSolver and
  3426 addSolver; added safe_asm_full_simp_tac;
  3427 
  3428 
  3429 *** HOL ***
  3430 
  3431 * a generic induction tactic `induct_tac' which works for all datatypes and
  3432 also for type `nat';
  3433 
  3434 * a generic case distinction tactic `exhaust_tac' which works for all
  3435 datatypes and also for type `nat';
  3436 
  3437 * each datatype comes with a function `size';
  3438 
  3439 * patterns in case expressions allow tuple patterns as arguments to
  3440 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  3441 
  3442 * primrec now also works with type nat;
  3443 
  3444 * recdef: a new declaration form, allows general recursive functions to be
  3445 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  3446 
  3447 * the constant for negation has been renamed from "not" to "Not" to
  3448 harmonize with FOL, ZF, LK, etc.;
  3449 
  3450 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  3451 infinite lists;
  3452 
  3453 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  3454 
  3455 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  3456 problems in commutative rings, using axiomatic type classes for + and *;
  3457 
  3458 * more examples in HOL/MiniML and HOL/Auth;
  3459 
  3460 * more default rewrite rules for quantifiers, union/intersection;
  3461 
  3462 * a new constant `arbitrary == @x.False';
  3463 
  3464 * HOLCF/IOA replaces old HOL/IOA;
  3465 
  3466 * HOLCF changes: derived all rules and arities
  3467   + axiomatic type classes instead of classes
  3468   + typedef instead of faking type definitions
  3469   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  3470   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  3471   + eliminated the types void, one, tr
  3472   + use unit lift and bool lift (with translations) instead of one and tr
  3473   + eliminated blift from Lift3.thy (use Def instead of blift)
  3474   all eliminated rules are derived as theorems --> no visible changes ;
  3475 
  3476 
  3477 *** ZF ***
  3478 
  3479 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  3480 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  3481 as ZF_cs addSIs [equalityI];
  3482 
  3483 
  3484 
  3485 New in Isabelle94-7 (November 96)
  3486 ---------------------------------
  3487 
  3488 * allowing negative levels (as offsets) in prlev and choplev;
  3489 
  3490 * super-linear speedup for large simplifications;
  3491 
  3492 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  3493 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  3494 FAIL); can suppress it using the command Delsimps (ex_simps @
  3495 all_simps); De Morgan laws are also now included, by default;
  3496 
  3497 * improved printing of ==>  :  ~:
  3498 
  3499 * new object-logic "Sequents" adds linear logic, while replacing LK
  3500 and Modal (thanks to Sara Kalvala);
  3501 
  3502 * HOL/Auth: correctness proofs for authentication protocols;
  3503 
  3504 * HOL: new auto_tac combines rewriting and classical reasoning (many
  3505 examples on HOL/Auth);
  3506 
  3507 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  3508 the rewriter and classical reasoner simultaneously;
  3509 
  3510 * function uresult no longer returns theorems in "standard" format;
  3511 regain previous version by: val uresult = standard o uresult;
  3512 
  3513 
  3514 
  3515 New in Isabelle94-6
  3516 -------------------
  3517 
  3518 * oracles -- these establish an interface between Isabelle and trusted
  3519 external reasoners, which may deliver results as theorems;
  3520 
  3521 * proof objects (in particular record all uses of oracles);
  3522 
  3523 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  3524 
  3525 * "constdefs" section in theory files;
  3526 
  3527 * "primrec" section (HOL) no longer requires names;
  3528 
  3529 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  3530 
  3531 
  3532 
  3533 New in Isabelle94-5
  3534 -------------------
  3535 
  3536 * reduced space requirements;
  3537 
  3538 * automatic HTML generation from theories;
  3539 
  3540 * theory files no longer require "..." (quotes) around most types;
  3541 
  3542 * new examples, including two proofs of the Church-Rosser theorem;
  3543 
  3544 * non-curried (1994) version of HOL is no longer distributed;
  3545 
  3546 
  3547 
  3548 New in Isabelle94-4
  3549 -------------------
  3550 
  3551 * greatly reduced space requirements;
  3552 
  3553 * theory files (.thy) no longer require \...\ escapes at line breaks;
  3554 
  3555 * searchable theorem database (see the section "Retrieving theorems" on
  3556 page 8 of the Reference Manual);
  3557 
  3558 * new examples, including Grabczewski's monumental case study of the
  3559 Axiom of Choice;
  3560 
  3561 * The previous version of HOL renamed to Old_HOL;
  3562 
  3563 * The new version of HOL (previously called CHOL) uses a curried syntax
  3564 for functions.  Application looks like f a b instead of f(a,b);
  3565 
  3566 * Mutually recursive inductive definitions finally work in HOL;
  3567 
  3568 * In ZF, pattern-matching on tuples is now available in all abstractions and
  3569 translates to the operator "split";
  3570 
  3571 
  3572 
  3573 New in Isabelle94-3
  3574 -------------------
  3575 
  3576 * new infix operator, addss, allowing the classical reasoner to
  3577 perform simplification at each step of its search.  Example:
  3578         fast_tac (cs addss ss)
  3579 
  3580 * a new logic, CHOL, the same as HOL, but with a curried syntax
  3581 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  3582 look like (a,b) instead of <a,b>;
  3583 
  3584 * PLEASE NOTE: CHOL will eventually replace HOL!
  3585 
  3586 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  3587 It translates to the operator "split".  A new theory of integers is available;
  3588 
  3589 * In ZF, integer numerals now denote two's-complement binary integers.
  3590 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  3591 
  3592 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  3593 of the Axiom of Choice;
  3594 
  3595 
  3596 
  3597 New in Isabelle94-2
  3598 -------------------
  3599 
  3600 * Significantly faster resolution;
  3601 
  3602 * the different sections in a .thy file can now be mixed and repeated
  3603 freely;
  3604 
  3605 * Database of theorems for FOL, HOL and ZF.  New
  3606 commands including qed, qed_goal and bind_thm store theorems in the database.
  3607 
  3608 * Simple database queries: return a named theorem (get_thm) or all theorems of
  3609 a given theory (thms_of), or find out what theory a theorem was proved in
  3610 (theory_of_thm);
  3611 
  3612 * Bugs fixed in the inductive definition and datatype packages;
  3613 
  3614 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  3615 and HOL_dup_cs obsolete;
  3616 
  3617 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  3618 have been removed;
  3619 
  3620 * Simpler definition of function space in ZF;
  3621 
  3622 * new results about cardinal and ordinal arithmetic in ZF;
  3623 
  3624 * 'subtype' facility in HOL for introducing new types as subsets of existing
  3625 types;
  3626 
  3627 
  3628 $Id$