NEWS
author wenzelm
Mon Jan 04 23:20:35 2010 +0100 (2010-01-04 ago)
changeset 34259 2ba492b8b6e8
parent 34255 2dd2547acb41
child 34933 0652d00305be
permissions -rw-r--r--
discontinued old TheoryDataFun, but retain Theory_Data_PP with is Pretty.pp argument to merge (still required in exotic situations -- hard to get rid of);
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** Pure ***
     8 
     9 * Code generator: details of internal data cache have no impact on
    10 the user space functionality any longer.
    11 
    12 
    13 *** HOL ***
    14 
    15 * Reorganized theory Sum_Type.thy; Inl and Inr now have
    16 authentic syntax.  INCOMPATIBILITY.
    17 
    18 * Code generation: ML and OCaml code is decorated with signatures.
    19 
    20 * Complete_Lattice.thy: lemmas top_def and bot_def have been replaced
    21 by the more convenient lemmas Inf_empty and Sup_empty.  Dropped lemmas
    22 Inf_insert_simp and Sup_insert_simp, which are subsumed by Inf_insert
    23 and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace former Inf_Univ
    24 and Sup_Univ.  Lemmas inf_top_right and sup_bot_right subsume inf_top
    25 and sup_bot respectively.  INCOMPATIBILITY.
    26 
    27 * Finite_Set.thy and List.thy: some lemmas have been generalized from
    28 sets to lattices:
    29 
    30   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
    31   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
    32   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
    33   union_Union_fold_union        ~> sup_Sup_fold_sup
    34   Inter_fold_inter              ~> Inf_fold_inf
    35   Union_fold_union              ~> Sup_fold_sup
    36   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
    37   union_UNION_fold_union        ~> sup_SUPR_fold_sup
    38   INTER_fold_inter              ~> INFI_fold_inf
    39   UNION_fold_union              ~> SUPR_fold_sup
    40 
    41 
    42 *** ML ***
    43 
    44 * Curried take and drop in library.ML; negative length is interpreted
    45 as infinity (as in chop).  INCOMPATIBILITY.
    46 
    47 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
    48 usual for resolution.  Rare INCOMPATIBILITY.
    49 
    50 * Discontinued old TheoryDataFun with its copy/init operation -- data
    51 needs to be pure.  Functor Theory_Data_PP retains the traditional
    52 Pretty.pp argument to merge, which is absent in the standard
    53 Theory_Data version.
    54 
    55 
    56 *** System ***
    57 
    58 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
    59 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
    60 proof terms are enabled unconditionally in the new HOL-Proofs image.
    61 
    62 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
    63 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
    64 respectively.
    65 
    66 
    67 
    68 New in Isabelle2009-1 (December 2009)
    69 -------------------------------------
    70 
    71 *** General ***
    72 
    73 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
    74 one backslash should be used, even in ML sources.
    75 
    76 
    77 *** Pure ***
    78 
    79 * Locale interpretation propagates mixins along the locale hierarchy.
    80 The currently only available mixins are the equations used to map
    81 local definitions to terms of the target domain of an interpretation.
    82 
    83 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
    84 loc" to print all interpretations of locale "loc" in the theory.
    85 Interpretations in proofs are not shown.
    86 
    87 * Thoroughly revised locales tutorial.  New section on conditional
    88 interpretation.
    89 
    90 * On instantiation of classes, remaining undefined class parameters
    91 are formally declared.  INCOMPATIBILITY.
    92 
    93 
    94 *** Document preparation ***
    95 
    96 * New generalized style concept for printing terms: @{foo (style) ...}
    97 instead of @{foo_style style ...}  (old form is still retained for
    98 backward compatibility).  Styles can be also applied for
    99 antiquotations prop, term_type and typeof.
   100 
   101 
   102 *** HOL ***
   103 
   104 * New proof method "smt" for a combination of first-order logic with
   105 equality, linear and nonlinear (natural/integer/real) arithmetic, and
   106 fixed-size bitvectors; there is also basic support for higher-order
   107 features (esp. lambda abstractions).  It is an incomplete decision
   108 procedure based on external SMT solvers using the oracle mechanism;
   109 for the SMT solver Z3, this method is proof-producing.  Certificates
   110 are provided to avoid calling the external solvers solely for
   111 re-checking proofs.  Due to a remote SMT service there is no need for
   112 installing SMT solvers locally.  See src/HOL/SMT.
   113 
   114 * New commands to load and prove verification conditions generated by
   115 the Boogie program verifier or derived systems (e.g. the Verifying C
   116 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
   117 
   118 * New counterexample generator tool 'nitpick' based on the Kodkod
   119 relational model finder.  See src/HOL/Tools/Nitpick and
   120 src/HOL/Nitpick_Examples.
   121 
   122 * New commands 'code_pred' and 'values' to invoke the predicate
   123 compiler and to enumerate values of inductive predicates.
   124 
   125 * A tabled implementation of the reflexive transitive closure.
   126 
   127 * New implementation of quickcheck uses generic code generator;
   128 default generators are provided for all suitable HOL types, records
   129 and datatypes.  Old quickcheck can be re-activated importing theory
   130 Library/SML_Quickcheck.
   131 
   132 * New testing tool Mirabelle for automated proof tools.  Applies
   133 several tools and tactics like sledgehammer, metis, or quickcheck, to
   134 every proof step in a theory.  To be used in batch mode via the
   135 "mirabelle" utility.
   136 
   137 * New proof method "sos" (sum of squares) for nonlinear real
   138 arithmetic (originally due to John Harison). It requires theory
   139 Library/Sum_Of_Squares.  It is not a complete decision procedure but
   140 works well in practice on quantifier-free real arithmetic with +, -,
   141 *, ^, =, <= and <, i.e. boolean combinations of equalities and
   142 inequalities between polynomials.  It makes use of external
   143 semidefinite programming solvers.  Method "sos" generates a
   144 certificate that can be pasted into the proof thus avoiding the need
   145 to call an external tool every time the proof is checked.  See
   146 src/HOL/Library/Sum_Of_Squares.
   147 
   148 * New method "linarith" invokes existing linear arithmetic decision
   149 procedure only.
   150 
   151 * New command 'atp_minimal' reduces result produced by Sledgehammer.
   152 
   153 * New Sledgehammer option "Full Types" in Proof General settings menu.
   154 Causes full type information to be output to the ATPs.  This slows
   155 ATPs down considerably but eliminates a source of unsound "proofs"
   156 that fail later.
   157 
   158 * New method "metisFT": A version of metis that uses full type
   159 information in order to avoid failures of proof reconstruction.
   160 
   161 * New evaluator "approximate" approximates an real valued term using
   162 the same method as the approximation method.
   163 
   164 * Method "approximate" now supports arithmetic expressions as
   165 boundaries of intervals and implements interval splitting and Taylor
   166 series expansion.
   167 
   168 * ML antiquotation @{code_datatype} inserts definition of a datatype
   169 generated by the code generator; e.g. see src/HOL/Predicate.thy.
   170 
   171 * New theory SupInf of the supremum and infimum operators for sets of
   172 reals.
   173 
   174 * New theory Probability, which contains a development of measure
   175 theory, eventually leading to Lebesgue integration and probability.
   176 
   177 * Extended Multivariate Analysis to include derivation and Brouwer's
   178 fixpoint theorem.
   179 
   180 * Reorganization of number theory, INCOMPATIBILITY:
   181   - new number theory development for nat and int, in theories Divides
   182     and GCD as well as in new session Number_Theory
   183   - some constants and facts now suffixed with _nat and _int
   184     accordingly
   185   - former session NumberTheory now named Old_Number_Theory, including
   186     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
   187   - moved theory Pocklington from src/HOL/Library to
   188     src/HOL/Old_Number_Theory
   189 
   190 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
   191 lcm of finite and infinite sets. It is shown that they form a complete
   192 lattice.
   193 
   194 * Class semiring_div requires superclass no_zero_divisors and proof of
   195 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
   196 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
   197 generalized to class semiring_div, subsuming former theorems
   198 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
   199 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
   200 INCOMPATIBILITY.
   201 
   202 * Refinements to lattice classes and sets:
   203   - less default intro/elim rules in locale variant, more default
   204     intro/elim rules in class variant: more uniformity
   205   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
   206     le_inf_iff
   207   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
   208     sup_aci)
   209   - renamed ACI to inf_sup_aci
   210   - new class "boolean_algebra"
   211   - class "complete_lattice" moved to separate theory
   212     "Complete_Lattice"; corresponding constants (and abbreviations)
   213     renamed and with authentic syntax:
   214     Set.Inf ~>    Complete_Lattice.Inf
   215     Set.Sup ~>    Complete_Lattice.Sup
   216     Set.INFI ~>   Complete_Lattice.INFI
   217     Set.SUPR ~>   Complete_Lattice.SUPR
   218     Set.Inter ~>  Complete_Lattice.Inter
   219     Set.Union ~>  Complete_Lattice.Union
   220     Set.INTER ~>  Complete_Lattice.INTER
   221     Set.UNION ~>  Complete_Lattice.UNION
   222   - authentic syntax for
   223     Set.Pow
   224     Set.image
   225   - mere abbreviations:
   226     Set.empty               (for bot)
   227     Set.UNIV                (for top)
   228     Set.inter               (for inf, formerly Set.Int)
   229     Set.union               (for sup, formerly Set.Un)
   230     Complete_Lattice.Inter  (for Inf)
   231     Complete_Lattice.Union  (for Sup)
   232     Complete_Lattice.INTER  (for INFI)
   233     Complete_Lattice.UNION  (for SUPR)
   234   - object-logic definitions as far as appropriate
   235 
   236 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
   237 Un_subset_iff are explicitly deleted as default simp rules; then also
   238 their lattice counterparts le_inf_iff and le_sup_iff have to be
   239 deleted to achieve the desired effect.
   240 
   241 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
   242 rules by default any longer; the same applies to min_max.inf_absorb1
   243 etc.  INCOMPATIBILITY.
   244 
   245 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
   246 pred_set_conv by default.  INCOMPATIBILITY.
   247 
   248 * Power operations on relations and functions are now one dedicated
   249 constant "compow" with infix syntax "^^".  Power operation on
   250 multiplicative monoids retains syntax "^" and is now defined generic
   251 in class power.  INCOMPATIBILITY.
   252 
   253 * Relation composition "R O S" now has a more standard argument order:
   254 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
   255 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
   256 break, since the O_assoc rule was not rewritten like this.  Fix using
   257 O_assoc[symmetric].  The same applies to the curried version "R OO S".
   258 
   259 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
   260 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
   261 INCOMPATIBILITY.
   262 
   263 * Most rules produced by inductive and datatype package have mandatory
   264 prefixes.  INCOMPATIBILITY.
   265 
   266 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
   267 the attribute of the same name.  Each of the theorems in the list
   268 DERIV_intros assumes composition with an additional function and
   269 matches a variable to the derivative, which has to be solved by the
   270 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
   271 of most elementary terms.  Former Maclauren.DERIV_tac and
   272 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
   273 INCOMPATIBILITY.
   274 
   275 * Code generator attributes follow the usual underscore convention:
   276     code_unfold     replaces    code unfold
   277     code_post       replaces    code post
   278     etc.
   279   INCOMPATIBILITY.
   280 
   281 * Renamed methods:
   282     sizechange -> size_change
   283     induct_scheme -> induction_schema
   284   INCOMPATIBILITY.
   285 
   286 * Discontinued abbreviation "arbitrary" of constant "undefined".
   287 INCOMPATIBILITY, use "undefined" directly.
   288 
   289 * Renamed theorems:
   290     Suc_eq_add_numeral_1 -> Suc_eq_plus1
   291     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
   292     Suc_plus1 -> Suc_eq_plus1
   293     *anti_sym -> *antisym*
   294     vector_less_eq_def -> vector_le_def
   295   INCOMPATIBILITY.
   296 
   297 * Added theorem List.map_map as [simp].  Removed List.map_compose.
   298 INCOMPATIBILITY.
   299 
   300 * Removed predicate "M hassize n" (<--> card M = n & finite M).
   301 INCOMPATIBILITY.
   302 
   303 
   304 *** HOLCF ***
   305 
   306 * Theory Representable defines a class "rep" of domains that are
   307 representable (via an ep-pair) in the universal domain type "udom".
   308 Instances are provided for all type constructors defined in HOLCF.
   309 
   310 * The 'new_domain' command is a purely definitional version of the
   311 domain package, for representable domains.  Syntax is identical to the
   312 old domain package.  The 'new_domain' package also supports indirect
   313 recursion using previously-defined type constructors.  See
   314 src/HOLCF/ex/New_Domain.thy for examples.
   315 
   316 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
   317 on the left-hand side of an equation, and then performs
   318 simplification.  Rewriting is done using rules declared with the
   319 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
   320 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
   321 
   322 * The pattern-match compiler in 'fixrec' can now handle constructors
   323 with HOL function types.  Pattern-match combinators for the Pair
   324 constructor are pre-configured.
   325 
   326 * The 'fixrec' package now produces better fixed-point induction rules
   327 for mutually-recursive definitions:  Induction rules have conclusions
   328 of the form "P foo bar" instead of "P <foo, bar>".
   329 
   330 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
   331 been renamed to "below".  The name "below" now replaces "less" in many
   332 theorem names.  (Legacy theorem names using "less" are still supported
   333 as well.)
   334 
   335 * The 'fixrec' package now supports "bottom patterns".  Bottom
   336 patterns can be used to generate strictness rules, or to make
   337 functions more strict (much like the bang-patterns supported by the
   338 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
   339 examples.
   340 
   341 
   342 *** ML ***
   343 
   344 * Support for Poly/ML 5.3.0, with improved reporting of compiler
   345 errors and run-time exceptions, including detailed source positions.
   346 
   347 * Structure Name_Space (formerly NameSpace) now manages uniquely
   348 identified entries, with some additional information such as source
   349 position, logical grouping etc.
   350 
   351 * Theory and context data is now introduced by the simplified and
   352 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
   353 to be pure, but the old TheoryDataFun for mutable data (with explicit
   354 copy operation) is still available for some time.
   355 
   356 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
   357 provides a high-level programming interface to synchronized state
   358 variables with atomic update.  This works via pure function
   359 application within a critical section -- its runtime should be as
   360 short as possible; beware of deadlocks if critical code is nested,
   361 either directly or indirectly via other synchronized variables!
   362 
   363 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
   364 wraps raw ML references, explicitly indicating their non-thread-safe
   365 behaviour.  The Isar toplevel keeps this structure open, to
   366 accommodate Proof General as well as quick and dirty interactive
   367 experiments with references.
   368 
   369 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
   370 parallel tactical reasoning.
   371 
   372 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
   373 are similar to SUBPROOF, but are slightly more flexible: only the
   374 specified parts of the subgoal are imported into the context, and the
   375 body tactic may introduce new subgoals and schematic variables.
   376 
   377 * Old tactical METAHYPS, which does not observe the proof context, has
   378 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
   379 or Subgoal.FOCUS etc.
   380 
   381 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
   382 functors have their own ML name space there is no point to mark them
   383 separately.)  Minor INCOMPATIBILITY.
   384 
   385 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
   386 
   387 * Renamed several structures FooBar to Foo_Bar.  Occasional,
   388 INCOMPATIBILITY.
   389 
   390 * Operations of structure Skip_Proof no longer require quick_and_dirty
   391 mode, which avoids critical setmp.
   392 
   393 * Eliminated old Attrib.add_attributes, Method.add_methods and related
   394 combinators for "args".  INCOMPATIBILITY, need to use simplified
   395 Attrib/Method.setup introduced in Isabelle2009.
   396 
   397 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
   398 back on global_simpset_of, global_claset_of, global_clasimpset_of as
   399 last resort.  INCOMPATIBILITY.
   400 
   401 * Display.pretty_thm now requires a proper context (cf. former
   402 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
   403 or even Display.pretty_thm_without_context as last resort.
   404 INCOMPATIBILITY.
   405 
   406 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
   407 Syntax.pretty_typ/term directly, preferably with proper context
   408 instead of global theory.
   409 
   410 
   411 *** System ***
   412 
   413 * Further fine tuning of parallel proof checking, scales up to 8 cores
   414 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
   415 usedir option -q.
   416 
   417 * Support for additional "Isabelle components" via etc/components, see
   418 also the system manual.
   419 
   420 * The isabelle makeall tool now operates on all components with
   421 IsaMakefile, not just hardwired "logics".
   422 
   423 * Removed "compress" option from isabelle-process and isabelle usedir;
   424 this is always enabled.
   425 
   426 * Discontinued support for Poly/ML 4.x versions.
   427 
   428 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
   429 on a given logic image.  This requires the lighttpd webserver and is
   430 currently supported on Linux only.
   431 
   432 
   433 
   434 New in Isabelle2009 (April 2009)
   435 --------------------------------
   436 
   437 *** General ***
   438 
   439 * Simplified main Isabelle executables, with less surprises on
   440 case-insensitive file-systems (such as Mac OS).
   441 
   442   - The main Isabelle tool wrapper is now called "isabelle" instead of
   443     "isatool."
   444 
   445   - The former "isabelle" alias for "isabelle-process" has been
   446     removed (should rarely occur to regular users).
   447 
   448   - The former "isabelle-interface" and its alias "Isabelle" have been
   449     removed (interfaces are now regular Isabelle tools).
   450 
   451 Within scripts and make files, the Isabelle environment variables
   452 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
   453 respectively.  (The latter are still available as legacy feature.)
   454 
   455 The old isabelle-interface wrapper could react in confusing ways if
   456 the interface was uninstalled or changed otherwise.  Individual
   457 interface tool configuration is now more explicit, see also the
   458 Isabelle system manual.  In particular, Proof General is now available
   459 via "isabelle emacs".
   460 
   461 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
   462 purge installed copies of Isabelle executables and re-run "isabelle
   463 install -p ...", or use symlinks.
   464 
   465 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
   466 old ~/isabelle, which was slightly non-standard and apt to cause
   467 surprises on case-insensitive file-systems (such as Mac OS).
   468 
   469 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
   470 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
   471 care is required when using older releases of Isabelle.  Note that
   472 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
   473 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
   474 
   475 * Proofs of fully specified statements are run in parallel on
   476 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
   477 a regular 4-core machine, if the initial heap space is made reasonably
   478 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
   479 
   480 * The main reference manuals ("isar-ref", "implementation", and
   481 "system") have been updated and extended.  Formally checked references
   482 as hyperlinks are now available uniformly.
   483 
   484 
   485 *** Pure ***
   486 
   487 * Complete re-implementation of locales.  INCOMPATIBILITY in several
   488 respects.  The most important changes are listed below.  See the
   489 Tutorial on Locales ("locales" manual) for details.
   490 
   491 - In locale expressions, instantiation replaces renaming.  Parameters
   492 must be declared in a for clause.  To aid compatibility with previous
   493 parameter inheritance, in locale declarations, parameters that are not
   494 'touched' (instantiation position "_" or omitted) are implicitly added
   495 with their syntax at the beginning of the for clause.
   496 
   497 - Syntax from abbreviations and definitions in locales is available in
   498 locale expressions and context elements.  The latter is particularly
   499 useful in locale declarations.
   500 
   501 - More flexible mechanisms to qualify names generated by locale
   502 expressions.  Qualifiers (prefixes) may be specified in locale
   503 expressions, and can be marked as mandatory (syntax: "name!:") or
   504 optional (syntax "name?:").  The default depends for plain "name:"
   505 depends on the situation where a locale expression is used: in
   506 commands 'locale' and 'sublocale' prefixes are optional, in
   507 'interpretation' and 'interpret' prefixes are mandatory.  The old
   508 implicit qualifiers derived from the parameter names of a locale are
   509 no longer generated.
   510 
   511 - Command "sublocale l < e" replaces "interpretation l < e".  The
   512 instantiation clause in "interpretation" and "interpret" (square
   513 brackets) is no longer available.  Use locale expressions.
   514 
   515 - When converting proof scripts, mandatory qualifiers in
   516 'interpretation' and 'interpret' should be retained by default, even
   517 if this is an INCOMPATIBILITY compared to former behavior.  In the
   518 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
   519 in locale expressions range over a single locale instance only.
   520 
   521 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
   522 In existing theorem specifications replace the includes element by the
   523 respective context elements of the included locale, omitting those
   524 that are already present in the theorem specification.  Multiple
   525 assume elements of a locale should be replaced by a single one
   526 involving the locale predicate.  In the proof body, declarations (most
   527 notably theorems) may be regained by interpreting the respective
   528 locales in the proof context as required (command "interpret").
   529 
   530 If using "includes" in replacement of a target solely because the
   531 parameter types in the theorem are not as general as in the target,
   532 consider declaring a new locale with additional type constraints on
   533 the parameters (context element "constrains").
   534 
   535 - Discontinued "locale (open)".  INCOMPATIBILITY.
   536 
   537 - Locale interpretation commands no longer attempt to simplify goal.
   538 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
   539 methods intro_locales and unfold_locales to clarify.
   540 
   541 - Locale interpretation commands no longer accept interpretation
   542 attributes.  INCOMPATIBILITY.
   543 
   544 * Class declaration: so-called "base sort" must not be given in import
   545 list any longer, but is inferred from the specification.  Particularly
   546 in HOL, write
   547 
   548     class foo = ...
   549 
   550 instead of
   551 
   552     class foo = type + ...
   553 
   554 * Class target: global versions of theorems stemming do not carry a
   555 parameter prefix any longer.  INCOMPATIBILITY.
   556 
   557 * Class 'instance' command no longer accepts attached definitions.
   558 INCOMPATIBILITY, use proper 'instantiation' target instead.
   559 
   560 * Recovered hiding of consts, which was accidentally broken in
   561 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
   562 makes c inaccessible; consider using ``hide (open) const c'' instead.
   563 
   564 * Slightly more coherent Pure syntax, with updated documentation in
   565 isar-ref manual.  Removed locales meta_term_syntax and
   566 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
   567 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
   568 directly in regular applications.
   569 
   570 * There is a new syntactic category "float_const" for signed decimal
   571 fractions (e.g. 123.45 or -123.45).
   572 
   573 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
   574 interface with 'setup' command instead.
   575 
   576 * Command 'local_setup' is similar to 'setup', but operates on a local
   577 theory context.
   578 
   579 * The 'axiomatization' command now only works within a global theory
   580 context.  INCOMPATIBILITY.
   581 
   582 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
   583 hypotheses.  Sorts required in the course of reasoning need to be
   584 covered by the constraints in the initial statement, completed by the
   585 type instance information of the background theory.  Non-trivial sort
   586 hypotheses, which rarely occur in practice, may be specified via
   587 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
   588 
   589   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
   590 
   591 The result contains an implicit sort hypotheses as before --
   592 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
   593 normalization.
   594 
   595 * Generalized Isar history, with support for linear undo, direct state
   596 addressing etc.
   597 
   598 * Changed defaults for unify configuration options:
   599 
   600   unify_trace_bound = 50 (formerly 25)
   601   unify_search_bound = 60 (formerly 30)
   602 
   603 * Different bookkeeping for code equations (INCOMPATIBILITY):
   604 
   605   a) On theory merge, the last set of code equations for a particular
   606      constant is taken (in accordance with the policy applied by other
   607      parts of the code generator framework).
   608 
   609   b) Code equations stemming from explicit declarations (e.g. code
   610      attribute) gain priority over default code equations stemming
   611      from definition, primrec, fun etc.
   612 
   613 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
   614 
   615 * Unified theorem tables for both code generators.  Thus [code
   616 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
   617 
   618 * Command 'find_consts' searches for constants based on type and name
   619 patterns, e.g.
   620 
   621     find_consts "_ => bool"
   622 
   623 By default, matching is against subtypes, but it may be restricted to
   624 the whole type.  Searching by name is possible.  Multiple queries are
   625 conjunctive and queries may be negated by prefixing them with a
   626 hyphen:
   627 
   628     find_consts strict: "_ => bool" name: "Int" -"int => int"
   629 
   630 * New 'find_theorems' criterion "solves" matches theorems that
   631 directly solve the current goal (modulo higher-order unification).
   632 
   633 * Auto solve feature for main theorem statements: whenever a new goal
   634 is stated, "find_theorems solves" is called; any theorems that could
   635 solve the lemma directly are listed as part of the goal state.
   636 Cf. associated options in Proof General Isabelle settings menu,
   637 enabled by default, with reasonable timeout for pathological cases of
   638 higher-order unification.
   639 
   640 
   641 *** Document preparation ***
   642 
   643 * Antiquotation @{lemma} now imitates a regular terminal proof,
   644 demanding keyword 'by' and supporting the full method expression
   645 syntax just like the Isar command 'by'.
   646 
   647 
   648 *** HOL ***
   649 
   650 * Integrated main parts of former image HOL-Complex with HOL.  Entry
   651 points Main and Complex_Main remain as before.
   652 
   653 * Logic image HOL-Plain provides a minimal HOL with the most important
   654 tools available (inductive, datatype, primrec, ...).  This facilitates
   655 experimentation and tool development.  Note that user applications
   656 (and library theories) should never refer to anything below theory
   657 Main, as before.
   658 
   659 * Logic image HOL-Main stops at theory Main, and thus facilitates
   660 experimentation due to shorter build times.
   661 
   662 * Logic image HOL-NSA contains theories of nonstandard analysis which
   663 were previously part of former HOL-Complex.  Entry point Hyperreal
   664 remains valid, but theories formerly using Complex_Main should now use
   665 new entry point Hypercomplex.
   666 
   667 * Generic ATP manager for Sledgehammer, based on ML threads instead of
   668 Posix processes.  Avoids potentially expensive forking of the ML
   669 process.  New thread-based implementation also works on non-Unix
   670 platforms (Cygwin).  Provers are no longer hardwired, but defined
   671 within the theory via plain ML wrapper functions.  Basic Sledgehammer
   672 commands are covered in the isar-ref manual.
   673 
   674 * Wrapper scripts for remote SystemOnTPTP service allows to use
   675 sledgehammer without local ATP installation (Vampire etc.). Other
   676 provers may be included via suitable ML wrappers, see also
   677 src/HOL/ATP_Linkup.thy.
   678 
   679 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
   680 menu.
   681 
   682 * The metis method no longer fails because the theorem is too trivial
   683 (contains the empty clause).
   684 
   685 * The metis method now fails in the usual manner, rather than raising
   686 an exception, if it determines that it cannot prove the theorem.
   687 
   688 * Method "coherent" implements a prover for coherent logic (see also
   689 src/Tools/coherent.ML).
   690 
   691 * Constants "undefined" and "default" replace "arbitrary".  Usually
   692 "undefined" is the right choice to replace "arbitrary", though
   693 logically there is no difference.  INCOMPATIBILITY.
   694 
   695 * Command "value" now integrates different evaluation mechanisms.  The
   696 result of the first successful evaluation mechanism is printed.  In
   697 square brackets a particular named evaluation mechanisms may be
   698 specified (currently, [SML], [code] or [nbe]).  See further
   699 src/HOL/ex/Eval_Examples.thy.
   700 
   701 * Normalization by evaluation now allows non-leftlinear equations.
   702 Declare with attribute [code nbe].
   703 
   704 * Methods "case_tac" and "induct_tac" now refer to the very same rules
   705 as the structured Isar versions "cases" and "induct", cf. the
   706 corresponding "cases" and "induct" attributes.  Mutual induction rules
   707 are now presented as a list of individual projections
   708 (e.g. foo_bar.inducts for types foo and bar); the old format with
   709 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
   710 rare situations a different rule is selected --- notably nested tuple
   711 elimination instead of former prod.exhaust: use explicit (case_tac t
   712 rule: prod.exhaust) here.
   713 
   714 * Attributes "cases", "induct", "coinduct" support "del" option.
   715 
   716 * Removed fact "case_split_thm", which duplicates "case_split".
   717 
   718 * The option datatype has been moved to a new theory Option.  Renamed
   719 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
   720 
   721 * New predicate "strict_mono" classifies strict functions on partial
   722 orders.  With strict functions on linear orders, reasoning about
   723 (in)equalities is facilitated by theorems "strict_mono_eq",
   724 "strict_mono_less_eq" and "strict_mono_less".
   725 
   726 * Some set operations are now proper qualified constants with
   727 authentic syntax.  INCOMPATIBILITY:
   728 
   729     op Int ~>   Set.Int
   730     op Un ~>    Set.Un
   731     INTER ~>    Set.INTER
   732     UNION ~>    Set.UNION
   733     Inter ~>    Set.Inter
   734     Union ~>    Set.Union
   735     {} ~>       Set.empty
   736     UNIV ~>     Set.UNIV
   737 
   738 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
   739 theory Set.
   740 
   741 * Auxiliary class "itself" has disappeared -- classes without any
   742 parameter are treated as expected by the 'class' command.
   743 
   744 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
   745 
   746 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
   747 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
   748 
   749 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
   750 method "approximation".  It proves formulas on real values by using
   751 interval arithmetic.  In the formulas are also the transcendental
   752 functions sin, cos, tan, atan, ln, exp and the constant pi are
   753 allowed. For examples see
   754 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
   755 
   756 * Theory "Reflection" now resides in HOL/Library.
   757 
   758 * Entry point to Word library now simply named "Word".
   759 INCOMPATIBILITY.
   760 
   761 * Made source layout more coherent with logical distribution
   762 structure:
   763 
   764     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
   765     src/HOL/Library/Code_Message.thy ~> src/HOL/
   766     src/HOL/Library/GCD.thy ~> src/HOL/
   767     src/HOL/Library/Order_Relation.thy ~> src/HOL/
   768     src/HOL/Library/Parity.thy ~> src/HOL/
   769     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
   770     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
   771     src/HOL/Real/Lubs.thy ~> src/HOL/
   772     src/HOL/Real/PReal.thy ~> src/HOL/
   773     src/HOL/Real/Rational.thy ~> src/HOL/
   774     src/HOL/Real/RComplete.thy ~> src/HOL/
   775     src/HOL/Real/RealDef.thy ~> src/HOL/
   776     src/HOL/Real/RealPow.thy ~> src/HOL/
   777     src/HOL/Real/Real.thy ~> src/HOL/
   778     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
   779     src/HOL/Complex/Complex.thy ~> src/HOL/
   780     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
   781     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
   782     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
   783     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
   784     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
   785     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
   786     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
   787     src/HOL/Hyperreal/Log.thy ~> src/HOL/
   788     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
   789     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
   790     src/HOL/Hyperreal/Series.thy ~> src/HOL/
   791     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
   792     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
   793     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
   794     src/HOL/Real/Float ~> src/HOL/Library/
   795     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
   796     src/HOL/Real/RealVector.thy ~> src/HOL/
   797 
   798     src/HOL/arith_data.ML ~> src/HOL/Tools
   799     src/HOL/hologic.ML ~> src/HOL/Tools
   800     src/HOL/simpdata.ML ~> src/HOL/Tools
   801     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
   802     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
   803     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
   804     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
   805     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
   806     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
   807     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
   808 
   809     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
   810     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
   811     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
   812     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
   813     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
   814     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
   815 
   816 * If methods "eval" and "evaluation" encounter a structured proof
   817 state with !!/==>, only the conclusion is evaluated to True (if
   818 possible), avoiding strange error messages.
   819 
   820 * Method "sizechange" automates termination proofs using (a
   821 modification of) the size-change principle.  Requires SAT solver.  See
   822 src/HOL/ex/Termination.thy for examples.
   823 
   824 * Simplifier: simproc for let expressions now unfolds if bound
   825 variable occurs at most once in let expression body.  INCOMPATIBILITY.
   826 
   827 * Method "arith": Linear arithmetic now ignores all inequalities when
   828 fast_arith_neq_limit is exceeded, instead of giving up entirely.
   829 
   830 * New attribute "arith" for facts that should always be used
   831 automatically by arithmetic. It is intended to be used locally in
   832 proofs, e.g.
   833 
   834   assumes [arith]: "x > 0"
   835 
   836 Global usage is discouraged because of possible performance impact.
   837 
   838 * New classes "top" and "bot" with corresponding operations "top" and
   839 "bot" in theory Orderings; instantiation of class "complete_lattice"
   840 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
   841 
   842 * Changed definition lemma "less_fun_def" in order to provide an
   843 instance for preorders on functions; use lemma "less_le" instead.
   844 INCOMPATIBILITY.
   845 
   846 * Theory Orderings: class "wellorder" moved here, with explicit
   847 induction rule "less_induct" as assumption.  For instantiation of
   848 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
   849 INCOMPATIBILITY.
   850 
   851 * Theory Orderings: added class "preorder" as superclass of "order".
   852 INCOMPATIBILITY: Instantiation proofs for order, linorder
   853 etc. slightly changed.  Some theorems named order_class.* now named
   854 preorder_class.*.
   855 
   856 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
   857 "diag" to "Id_on".
   858 
   859 * Theory Finite_Set: added a new fold combinator of type
   860 
   861   ('a => 'b => 'b) => 'b => 'a set => 'b
   862 
   863 Occasionally this is more convenient than the old fold combinator
   864 which is now defined in terms of the new one and renamed to
   865 fold_image.
   866 
   867 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
   868 and "ring_simps" have been replaced by "algebra_simps" (which can be
   869 extended with further lemmas!).  At the moment both still exist but
   870 the former will disappear at some point.
   871 
   872 * Theory Power: Lemma power_Suc is now declared as a simp rule in
   873 class recpower.  Type-specific simp rules for various recpower types
   874 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
   875 
   876 rat_power_0    -> power_0
   877 rat_power_Suc  -> power_Suc
   878 realpow_0      -> power_0
   879 realpow_Suc    -> power_Suc
   880 complexpow_0   -> power_0
   881 complexpow_Suc -> power_Suc
   882 power_poly_0   -> power_0
   883 power_poly_Suc -> power_Suc
   884 
   885 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
   886 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
   887 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
   888 of lemmas from Divides has been generalized from nat to class
   889 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
   890 renames resulting from duplicate elimination:
   891 
   892     dvd_def_mod ~>          dvd_eq_mod_eq_0
   893     zero_dvd_iff ~>         dvd_0_left_iff
   894     dvd_0 ~>                dvd_0_right
   895     DIVISION_BY_ZERO_DIV ~> div_by_0
   896     DIVISION_BY_ZERO_MOD ~> mod_by_0
   897     mult_div ~>             div_mult_self2_is_id
   898     mult_mod ~>             mod_mult_self2_is_0
   899 
   900 * Theory IntDiv: removed many lemmas that are instances of class-based
   901 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
   902 rename old lemmas as follows:
   903 
   904 dvd_diff               -> nat_dvd_diff
   905 dvd_zminus_iff         -> dvd_minus_iff
   906 mod_add1_eq            -> mod_add_eq
   907 mod_mult1_eq           -> mod_mult_right_eq
   908 mod_mult1_eq'          -> mod_mult_left_eq
   909 mod_mult_distrib_mod   -> mod_mult_eq
   910 nat_mod_add_left_eq    -> mod_add_left_eq
   911 nat_mod_add_right_eq   -> mod_add_right_eq
   912 nat_mod_div_trivial    -> mod_div_trivial
   913 nat_mod_mod_trivial    -> mod_mod_trivial
   914 zdiv_zadd_self1        -> div_add_self1
   915 zdiv_zadd_self2        -> div_add_self2
   916 zdiv_zmult_self1       -> div_mult_self2_is_id
   917 zdiv_zmult_self2       -> div_mult_self1_is_id
   918 zdvd_triv_left         -> dvd_triv_left
   919 zdvd_triv_right        -> dvd_triv_right
   920 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
   921 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
   922 zmod_zadd_left_eq      -> mod_add_left_eq
   923 zmod_zadd_right_eq     -> mod_add_right_eq
   924 zmod_zadd_self1        -> mod_add_self1
   925 zmod_zadd_self2        -> mod_add_self2
   926 zmod_zadd1_eq          -> mod_add_eq
   927 zmod_zdiff1_eq         -> mod_diff_eq
   928 zmod_zdvd_zmod         -> mod_mod_cancel
   929 zmod_zmod_cancel       -> mod_mod_cancel
   930 zmod_zmult_self1       -> mod_mult_self2_is_0
   931 zmod_zmult_self2       -> mod_mult_self1_is_0
   932 zmod_1                 -> mod_by_1
   933 zdiv_1                 -> div_by_1
   934 zdvd_abs1              -> abs_dvd_iff
   935 zdvd_abs2              -> dvd_abs_iff
   936 zdvd_refl              -> dvd_refl
   937 zdvd_trans             -> dvd_trans
   938 zdvd_zadd              -> dvd_add
   939 zdvd_zdiff             -> dvd_diff
   940 zdvd_zminus_iff        -> dvd_minus_iff
   941 zdvd_zminus2_iff       -> minus_dvd_iff
   942 zdvd_zmultD            -> dvd_mult_right
   943 zdvd_zmultD2           -> dvd_mult_left
   944 zdvd_zmult_mono        -> mult_dvd_mono
   945 zdvd_0_right           -> dvd_0_right
   946 zdvd_0_left            -> dvd_0_left_iff
   947 zdvd_1_left            -> one_dvd
   948 zminus_dvd_iff         -> minus_dvd_iff
   949 
   950 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
   951 
   952 * The real numbers offer decimal input syntax: 12.34 is translated
   953 into 1234/10^2. This translation is not reversed upon output.
   954 
   955 * Theory Library/Polynomial defines an abstract type 'a poly of
   956 univariate polynomials with coefficients of type 'a.  In addition to
   957 the standard ring operations, it also supports div and mod.  Code
   958 generation is also supported, using list-style constructors.
   959 
   960 * Theory Library/Inner_Product defines a class of real_inner for real
   961 inner product spaces, with an overloaded operation inner :: 'a => 'a
   962 => real.  Class real_inner is a subclass of real_normed_vector from
   963 theory RealVector.
   964 
   965 * Theory Library/Product_Vector provides instances for the product
   966 type 'a * 'b of several classes from RealVector and Inner_Product.
   967 Definitions of addition, subtraction, scalar multiplication, norms,
   968 and inner products are included.
   969 
   970 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
   971 addition to the field operations, numerals and case syntax are also
   972 supported.
   973 
   974 * Theory Library/Diagonalize provides constructive version of Cantor's
   975 first diagonalization argument.
   976 
   977 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
   978 zlcm (for int); carried together from various gcd/lcm developements in
   979 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
   980 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
   981 may recover tupled syntax as follows:
   982 
   983     hide (open) const gcd
   984     abbreviation gcd where
   985       "gcd == (%(a, b). GCD.gcd a b)"
   986     notation (output)
   987       GCD.gcd ("gcd '(_, _')")
   988 
   989 The same works for lcm, zgcd, zlcm.
   990 
   991 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
   992 instantiations for algebraic structures.  Removed some duplicate
   993 theorems.  Changes in simp rules.  INCOMPATIBILITY.
   994 
   995 * ML antiquotation @{code} takes a constant as argument and generates
   996 corresponding code in background and inserts name of the corresponding
   997 resulting ML value/function/datatype constructor binding in place.
   998 All occurrences of @{code} with a single ML block are generated
   999 simultaneously.  Provides a generic and safe interface for
  1000 instrumentalizing code generation.  See
  1001 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  1002 In future you ought to refrain from ad-hoc compiling generated SML
  1003 code on the ML toplevel.  Note that (for technical reasons) @{code}
  1004 cannot refer to constants for which user-defined serializations are
  1005 set.  Refer to the corresponding ML counterpart directly in that
  1006 cases.
  1007 
  1008 * Command 'rep_datatype': instead of theorem names the command now
  1009 takes a list of terms denoting the constructors of the type to be
  1010 represented as datatype.  The characteristic theorems have to be
  1011 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  1012 have disappeared in favour of existing ones:
  1013 
  1014     unit_induct                 ~> unit.induct
  1015     prod_induct                 ~> prod.induct
  1016     sum_induct                  ~> sum.induct
  1017     Suc_Suc_eq                  ~> nat.inject
  1018     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  1019 
  1020 
  1021 *** HOL-Algebra ***
  1022 
  1023 * New locales for orders and lattices where the equivalence relation
  1024 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  1025 locales use a record structure with field eq for the equivalence.
  1026 
  1027 * New theory of factorial domains.
  1028 
  1029 * Units_l_inv and Units_r_inv are now simp rules by default.
  1030 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  1031 and/or r_inv will now also require deletion of these lemmas.
  1032 
  1033 * Renamed the following theorems, INCOMPATIBILITY:
  1034 
  1035 UpperD ~> Upper_memD
  1036 LowerD ~> Lower_memD
  1037 least_carrier ~> least_closed
  1038 greatest_carrier ~> greatest_closed
  1039 greatest_Lower_above ~> greatest_Lower_below
  1040 one_zero ~> carrier_one_zero
  1041 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  1042 
  1043 
  1044 *** HOL-Nominal ***
  1045 
  1046 * Nominal datatypes can now contain type-variables.
  1047 
  1048 * Commands 'nominal_inductive' and 'equivariance' work with local
  1049 theory targets.
  1050 
  1051 * Nominal primrec can now works with local theory targets and its
  1052 specification syntax now conforms to the general format as seen in
  1053 'inductive' etc.
  1054 
  1055 * Method "perm_simp" honours the standard simplifier attributes
  1056 (no_asm), (no_asm_use) etc.
  1057 
  1058 * The new predicate #* is defined like freshness, except that on the
  1059 left hand side can be a set or list of atoms.
  1060 
  1061 * Experimental command 'nominal_inductive2' derives strong induction
  1062 principles for inductive definitions.  In contrast to
  1063 'nominal_inductive', which can only deal with a fixed number of
  1064 binders, it can deal with arbitrary expressions standing for sets of
  1065 atoms to be avoided.  The only inductive definition we have at the
  1066 moment that needs this generalisation is the typing rule for Lets in
  1067 the algorithm W:
  1068 
  1069  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  1070  -----------------------------------------------------------------
  1071          Gamma |- Let x be t1 in t2 : T2
  1072 
  1073 In this rule one wants to avoid all the binders that are introduced by
  1074 "close Gamma T1".  We are looking for other examples where this
  1075 feature might be useful.  Please let us know.
  1076 
  1077 
  1078 *** HOLCF ***
  1079 
  1080 * Reimplemented the simplification procedure for proving continuity
  1081 subgoals.  The new simproc is extensible; users can declare additional
  1082 continuity introduction rules with the attribute [cont2cont].
  1083 
  1084 * The continuity simproc now uses a different introduction rule for
  1085 solving continuity subgoals on terms with lambda abstractions.  In
  1086 some rare cases the new simproc may fail to solve subgoals that the
  1087 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  1088 Potential INCOMPATIBILITY.
  1089 
  1090 * Command 'fixrec': specification syntax now conforms to the general
  1091 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  1092 examples.  INCOMPATIBILITY.
  1093 
  1094 
  1095 *** ZF ***
  1096 
  1097 * Proof of Zorn's Lemma for partial orders.
  1098 
  1099 
  1100 *** ML ***
  1101 
  1102 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  1103 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  1104 depends on multithreading, so timouts will not work before Poly/ML
  1105 5.2.1!
  1106 
  1107 * High-level support for concurrent ML programming, see
  1108 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  1109 particularly convenient to organize independent functional
  1110 computations.  The concept of "synchronized variables" provides a
  1111 higher-order interface for components with shared state, avoiding the
  1112 delicate details of mutexes and condition variables.  (Requires
  1113 Poly/ML 5.2.1 or later.)
  1114 
  1115 * ML bindings produced via Isar commands are stored within the Isar
  1116 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  1117 become thread-safe and work with undo as expected (concerning
  1118 top-level bindings, not side-effects on global references).
  1119 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  1120 compiler at runtime; really global bindings need to be given outside a
  1121 theory.  (Requires Poly/ML 5.2 or later.)
  1122 
  1123 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  1124 context.  Top-level ML bindings are stored within the proof context in
  1125 a purely sequential fashion, disregarding the nested proof structure.
  1126 ML bindings introduced by 'ML_prf' are discarded at the end of the
  1127 proof.  (Requires Poly/ML 5.2 or later.)
  1128 
  1129 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  1130 and Method.setup, as well as Isar commands 'attribute_setup' and
  1131 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  1132 existing code accordingly, or use plain 'setup' together with old
  1133 Method.add_method.
  1134 
  1135 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  1136 to 'a -> thm, while results are always tagged with an authentic oracle
  1137 name.  The Isar command 'oracle' is now polymorphic, no argument type
  1138 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  1139 accordingly.  Note that extra performance may be gained by producing
  1140 the cterm carefully, avoiding slow Thm.cterm_of.
  1141 
  1142 * Simplified interface for defining document antiquotations via
  1143 ThyOutput.antiquotation, ThyOutput.output, and optionally
  1144 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  1145 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  1146 examples.
  1147 
  1148 * More systematic treatment of long names, abstract name bindings, and
  1149 name space operations.  Basic operations on qualified names have been
  1150 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  1151 Long_Name.append.  Old type bstring has been mostly replaced by
  1152 abstract type binding (see structure Binding), which supports precise
  1153 qualification by packages and local theory targets, as well as proper
  1154 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  1155 bstring values into Binding.name, or better pass through abstract
  1156 bindings everywhere.  See further src/Pure/General/long_name.ML,
  1157 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  1158 
  1159 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  1160 LocalTheory.note etc.) now refer to the *full* internal name, not the
  1161 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  1162 
  1163 * Disposed old type and term read functions (Sign.read_def_typ,
  1164 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  1165 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  1166 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  1167 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  1168 resort for legacy applications.
  1169 
  1170 * Disposed old declarations, tactics, tactic combinators that refer to
  1171 the simpset or claset of an implicit theory (such as Addsimps,
  1172 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  1173 embedded ML text, or local_simpset_of with a proper context passed as
  1174 explicit runtime argument.
  1175 
  1176 * Rules and tactics that read instantiations (read_instantiate,
  1177 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  1178 context, which is required for parsing and type-checking.  Moreover,
  1179 the variables are specified as plain indexnames, not string encodings
  1180 thereof.  INCOMPATIBILITY.
  1181 
  1182 * Generic Toplevel.add_hook interface allows to analyze the result of
  1183 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  1184 for theorem dependency output of transactions resulting in a new
  1185 theory state.
  1186 
  1187 * ML antiquotations: block-structured compilation context indicated by
  1188 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  1189 
  1190   @{binding name}                         - basic name binding
  1191   @{let ?pat = term}                      - term abbreviation (HO matching)
  1192   @{note name = fact}                     - fact abbreviation
  1193   @{thm fact}                             - singleton fact (with attributes)
  1194   @{thms fact}                            - general fact (with attributes)
  1195   @{lemma prop by method}                 - singleton goal
  1196   @{lemma prop by meth1 meth2}            - singleton goal
  1197   @{lemma prop1 ... propN by method}      - general goal
  1198   @{lemma prop1 ... propN by meth1 meth2} - general goal
  1199   @{lemma (open) ...}                     - open derivation
  1200 
  1201 
  1202 *** System ***
  1203 
  1204 * The Isabelle "emacs" tool provides a specific interface to invoke
  1205 Proof General / Emacs, with more explicit failure if that is not
  1206 installed (the old isabelle-interface script silently falls back on
  1207 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  1208 installation location of the Proof General distribution.
  1209 
  1210 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  1211 the Isabelle process into a JVM/Scala application.  See
  1212 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  1213 process wrapper has been discontinued.)
  1214 
  1215 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  1216 
  1217 * Various status messages (with exact source position information) are
  1218 emitted, if proper markup print mode is enabled.  This allows
  1219 user-interface components to provide detailed feedback on internal
  1220 prover operations.
  1221 
  1222 
  1223 
  1224 New in Isabelle2008 (June 2008)
  1225 -------------------------------
  1226 
  1227 *** General ***
  1228 
  1229 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  1230 and updated, with formally checked references as hyperlinks.
  1231 
  1232 * Theory loader: use_thy (and similar operations) no longer set the
  1233 implicit ML context, which was occasionally hard to predict and in
  1234 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  1235 provides a proper context already.
  1236 
  1237 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1238 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  1239 'use' within a theory file will do the job.
  1240 
  1241 * Name space merge now observes canonical order, i.e. the second space
  1242 is inserted into the first one, while existing entries in the first
  1243 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  1244 swap theory imports.
  1245 
  1246 * Syntax: symbol \<chi> is now considered a letter.  Potential
  1247 INCOMPATIBILITY in identifier syntax etc.
  1248 
  1249 * Outer syntax: string tokens no longer admit escaped white space,
  1250 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  1251 white space without escapes.
  1252 
  1253 * Outer syntax: string tokens may contain arbitrary character codes
  1254 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  1255 "foo_bar".
  1256 
  1257 
  1258 *** Pure ***
  1259 
  1260 * Context-dependent token translations.  Default setup reverts locally
  1261 fixed variables, and adds hilite markup for undeclared frees.
  1262 
  1263 * Unused theorems can be found using the new command 'unused_thms'.
  1264 There are three ways of invoking it:
  1265 
  1266 (1) unused_thms
  1267      Only finds unused theorems in the current theory.
  1268 
  1269 (2) unused_thms thy_1 ... thy_n -
  1270      Finds unused theorems in the current theory and all of its ancestors,
  1271      excluding the theories thy_1 ... thy_n and all of their ancestors.
  1272 
  1273 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  1274      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  1275      their ancestors, excluding the theories thy_1 ... thy_n and all of
  1276      their ancestors.
  1277 
  1278 In order to increase the readability of the list produced by
  1279 unused_thms, theorems that have been created by a particular instance
  1280 of a theory command such as 'inductive' or 'function' are considered
  1281 to belong to the same "group", meaning that if at least one theorem in
  1282 this group is used, the other theorems in the same group are no longer
  1283 reported as unused.  Moreover, if all theorems in the group are
  1284 unused, only one theorem in the group is displayed.
  1285 
  1286 Note that proof objects have to be switched on in order for
  1287 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  1288 usually the case when using Proof General with the default settings).
  1289 
  1290 * Authentic naming of facts disallows ad-hoc overwriting of previous
  1291 theorems within the same name space.  INCOMPATIBILITY, need to remove
  1292 duplicate fact bindings, or even accidental fact duplications.  Note
  1293 that tools may maintain dynamically scoped facts systematically, using
  1294 PureThy.add_thms_dynamic.
  1295 
  1296 * Command 'hide' now allows to hide from "fact" name space as well.
  1297 
  1298 * Eliminated destructive theorem database, simpset, claset, and
  1299 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  1300 update of theories within ML code.
  1301 
  1302 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  1303 INCOMPATIBILITY, object-logics depending on former Pure require
  1304 additional setup PureThy.old_appl_syntax_setup; object-logics
  1305 depending on former CPure need to refer to Pure.
  1306 
  1307 * Commands 'use' and 'ML' are now purely functional, operating on
  1308 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  1309 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  1310 INCOMPATIBILITY.
  1311 
  1312 * Command 'setup': discontinued implicit version with ML reference.
  1313 
  1314 * Instantiation target allows for simultaneous specification of class
  1315 instance operations together with an instantiation proof.
  1316 Type-checking phase allows to refer to class operations uniformly.
  1317 See src/HOL/Complex/Complex.thy for an Isar example and
  1318 src/HOL/Library/Eval.thy for an ML example.
  1319 
  1320 * Indexing of literal facts: be more serious about including only
  1321 facts from the visible specification/proof context, but not the
  1322 background context (locale etc.).  Affects `prop` notation and method
  1323 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  1324 situations.
  1325 
  1326 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  1327 "(open)" option, which used to expose internal bound variables to the
  1328 proof text.
  1329 
  1330 * Isar statements: removed obsolete case "rule_context".
  1331 INCOMPATIBILITY, better use explicit fixes/assumes.
  1332 
  1333 * Locale proofs: default proof step now includes 'unfold_locales';
  1334 hence 'proof' without argument may be used to unfold locale
  1335 predicates.
  1336 
  1337 
  1338 *** Document preparation ***
  1339 
  1340 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  1341 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  1342 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  1343 spot); renamed link color from "darkblue" to "linkcolor" (default
  1344 value unchanged, can be redefined via \definecolor); no longer sets
  1345 "a4paper" option (unnecessary or even intrusive).
  1346 
  1347 * Antiquotation @{lemma A method} proves proposition A by the given
  1348 method (either a method name or a method name plus (optional) method
  1349 arguments in parentheses) and prints A just like @{prop A}.
  1350 
  1351 
  1352 *** HOL ***
  1353 
  1354 * New primrec package.  Specification syntax conforms in style to
  1355 definition/function/....  No separate induction rule is provided.  The
  1356 "primrec" command distinguishes old-style and new-style specifications
  1357 by syntax.  The former primrec package is now named OldPrimrecPackage.
  1358 When adjusting theories, beware: constants stemming from new-style
  1359 primrec specifications have authentic syntax.
  1360 
  1361 * Metis prover is now an order of magnitude faster, and also works
  1362 with multithreading.
  1363 
  1364 * Metis: the maximum number of clauses that can be produced from a
  1365 theorem is now given by the attribute max_clauses.  Theorems that
  1366 exceed this number are ignored, with a warning printed.
  1367 
  1368 * Sledgehammer no longer produces structured proofs by default. To
  1369 enable, declare [[sledgehammer_full = true]].  Attributes
  1370 reconstruction_modulus, reconstruction_sorts renamed
  1371 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  1372 
  1373 * Method "induct_scheme" derives user-specified induction rules
  1374 from well-founded induction and completeness of patterns. This factors
  1375 out some operations that are done internally by the function package
  1376 and makes them available separately.  See
  1377 src/HOL/ex/Induction_Scheme.thy for examples.
  1378 
  1379 * More flexible generation of measure functions for termination
  1380 proofs: Measure functions can be declared by proving a rule of the
  1381 form "is_measure f" and giving it the [measure_function] attribute.
  1382 The "is_measure" predicate is logically meaningless (always true), and
  1383 just guides the heuristic.  To find suitable measure functions, the
  1384 termination prover sets up the goal "is_measure ?f" of the appropriate
  1385 type and generates all solutions by prolog-style backwards proof using
  1386 the declared rules.
  1387 
  1388 This setup also deals with rules like 
  1389 
  1390   "is_measure f ==> is_measure (list_size f)"
  1391 
  1392 which accommodates nested datatypes that recurse through lists.
  1393 Similar rules are predeclared for products and option types.
  1394 
  1395 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  1396 
  1397   INCOMPATIBILITIES:
  1398 
  1399   - Definitions of overloaded constants on sets have to be replaced by
  1400     definitions on => and bool.
  1401 
  1402   - Some definitions of overloaded operators on sets can now be proved
  1403     using the definitions of the operators on => and bool.  Therefore,
  1404     the following theorems have been renamed:
  1405 
  1406       subset_def   -> subset_eq
  1407       psubset_def  -> psubset_eq
  1408       set_diff_def -> set_diff_eq
  1409       Compl_def    -> Compl_eq
  1410       Sup_set_def  -> Sup_set_eq
  1411       Inf_set_def  -> Inf_set_eq
  1412       sup_set_def  -> sup_set_eq
  1413       inf_set_def  -> inf_set_eq
  1414 
  1415   - Due to the incompleteness of the HO unification algorithm, some
  1416     rules such as subst may require manual instantiation, if some of
  1417     the unknowns in the rule is a set.
  1418 
  1419   - Higher order unification and forward proofs:
  1420     The proof pattern
  1421 
  1422       have "P (S::'a set)" <...>
  1423       then have "EX S. P S" ..
  1424 
  1425     no longer works (due to the incompleteness of the HO unification
  1426     algorithm) and must be replaced by the pattern
  1427 
  1428       have "EX S. P S"
  1429       proof
  1430         show "P S" <...>
  1431       qed
  1432 
  1433   - Calculational reasoning with subst (or similar rules):
  1434     The proof pattern
  1435 
  1436       have "P (S::'a set)" <...>
  1437       also have "S = T" <...>
  1438       finally have "P T" .
  1439 
  1440     no longer works (for similar reasons as the previous example) and
  1441     must be replaced by something like
  1442 
  1443       have "P (S::'a set)" <...>
  1444       moreover have "S = T" <...>
  1445       ultimately have "P T" by simp
  1446 
  1447   - Tactics or packages written in ML code:
  1448     Code performing pattern matching on types via
  1449 
  1450       Type ("set", [T]) => ...
  1451 
  1452     must be rewritten. Moreover, functions like strip_type or
  1453     binder_types no longer return the right value when applied to a
  1454     type of the form
  1455 
  1456       T1 => ... => Tn => U => bool
  1457 
  1458     rather than
  1459 
  1460       T1 => ... => Tn => U set
  1461 
  1462 * Merged theories Wellfounded_Recursion, Accessible_Part and
  1463 Wellfounded_Relations to theory Wellfounded.
  1464 
  1465 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  1466 
  1467 * Class finite no longer treats UNIV as class parameter.  Use class
  1468 enum from theory Library/Enum instead to achieve a similar effect.
  1469 INCOMPATIBILITY.
  1470 
  1471 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  1472 and "Cons".  INCOMPATIBILITY.
  1473 
  1474 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  1475 Potential INCOMPATIBILITY.
  1476 
  1477 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  1478 injective_fst_snd removed, use split_eta and prod_eqI instead.
  1479 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  1480 
  1481 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  1482 the same name in theory Orderings:
  1483 
  1484   less_trans
  1485   less_linear
  1486   le_imp_less_or_eq
  1487   le_less_trans
  1488   less_le_trans
  1489   less_not_sym
  1490   less_asym
  1491 
  1492 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  1493 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  1494 and different variable names.
  1495 
  1496 * Library/Option_ord.thy: Canonical order on option type.
  1497 
  1498 * Library/RBT.thy: Red-black trees, an efficient implementation of
  1499 finite maps.
  1500 
  1501 * Library/Countable.thy: Type class for countable types.
  1502 
  1503 * Theory Int: The representation of numerals has changed.  The infix
  1504 operator BIT and the bit datatype with constructors B0 and B1 have
  1505 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  1506 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  1507 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  1508 accordingly.
  1509 
  1510 * Theory Nat: definition of <= and < on natural numbers no longer
  1511 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  1512 le_def and less_def have disappeared.  Consider lemmas not_less
  1513 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  1514 
  1515 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  1516 (whose purpose mainly is for various fold_set functionals) have been
  1517 abandoned in favor of the existing algebraic classes
  1518 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  1519 lower_semilattice (resp. upper_semilattice) and linorder.
  1520 INCOMPATIBILITY.
  1521 
  1522 * Theory Transitive_Closure: induct and cases rules now declare proper
  1523 case_names ("base" and "step").  INCOMPATIBILITY.
  1524 
  1525 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  1526 lattices.  The form set-specific version is available as
  1527 Inductive.lfp_ordinal_induct_set.
  1528 
  1529 * Renamed theorems "power.simps" to "power_int.simps".
  1530 INCOMPATIBILITY.
  1531 
  1532 * Class semiring_div provides basic abstract properties of semirings
  1533 with division and modulo operations.  Subsumes former class dvd_mod.
  1534 
  1535 * Merged theories IntDef, Numeral and IntArith into unified theory
  1536 Int.  INCOMPATIBILITY.
  1537 
  1538 * Theory Library/Code_Index: type "index" now represents natural
  1539 numbers rather than integers.  INCOMPATIBILITY.
  1540 
  1541 * New class "uminus" with operation "uminus" (split of from class
  1542 "minus" which now only has operation "minus", binary).
  1543 INCOMPATIBILITY.
  1544 
  1545 * Constants "card", "internal_split", "option_map" now with authentic
  1546 syntax.  INCOMPATIBILITY.
  1547 
  1548 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  1549 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  1550 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  1551 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  1552 Sup_set_def, le_def, less_def, option_map_def now with object
  1553 equality.  INCOMPATIBILITY.
  1554 
  1555 * Records. Removed K_record, and replaced it by pure lambda term
  1556 %x. c. The simplifier setup is now more robust against eta expansion.
  1557 INCOMPATIBILITY: in cases explicitly referring to K_record.
  1558 
  1559 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  1560 
  1561 * Library/ListVector: new theory of arithmetic vector operations.
  1562 
  1563 * Library/Order_Relation: new theory of various orderings as sets of
  1564 pairs.  Defines preorders, partial orders, linear orders and
  1565 well-orders on sets and on types.
  1566 
  1567 
  1568 *** ZF ***
  1569 
  1570 * Renamed some theories to allow to loading both ZF and HOL in the
  1571 same session:
  1572 
  1573   Datatype  -> Datatype_ZF
  1574   Inductive -> Inductive_ZF
  1575   Int       -> Int_ZF
  1576   IntDiv    -> IntDiv_ZF
  1577   Nat       -> Nat_ZF
  1578   List      -> List_ZF
  1579   Main      -> Main_ZF
  1580 
  1581 INCOMPATIBILITY: ZF theories that import individual theories below
  1582 Main might need to be adapted.  Regular theory Main is still
  1583 available, as trivial extension of Main_ZF.
  1584 
  1585 
  1586 *** ML ***
  1587 
  1588 * ML within Isar: antiquotation @{const name} or @{const
  1589 name(typargs)} produces statically-checked Const term.
  1590 
  1591 * Functor NamedThmsFun: data is available to the user as dynamic fact
  1592 (of the same name).  Removed obsolete print command.
  1593 
  1594 * Removed obsolete "use_legacy_bindings" function.
  1595 
  1596 * The ``print mode'' is now a thread-local value derived from a global
  1597 template (the former print_mode reference), thus access becomes
  1598 non-critical.  The global print_mode reference is for session
  1599 management only; user-code should use print_mode_value,
  1600 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  1601 
  1602 * Functions system/system_out provide a robust way to invoke external
  1603 shell commands, with propagation of interrupts (requires Poly/ML
  1604 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  1605 
  1606 
  1607 *** System ***
  1608 
  1609 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  1610 in accordance with Proof General 3.7, which prefers GNU emacs.
  1611 
  1612 * isatool tty runs Isabelle process with plain tty interaction;
  1613 optional line editor may be specified via ISABELLE_LINE_EDITOR
  1614 setting, the default settings attempt to locate "ledit" and "rlwrap".
  1615 
  1616 * isatool browser now works with Cygwin as well, using general
  1617 "javapath" function defined in Isabelle process environment.
  1618 
  1619 * YXML notation provides a simple and efficient alternative to
  1620 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  1621 isatool yxml as described in the Isabelle system manual.
  1622 
  1623 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  1624 provides general wrapper for managing an Isabelle process in a robust
  1625 fashion, with ``cooked'' output from stdin/stderr.
  1626 
  1627 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  1628 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  1629 
  1630 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  1631 way of changing the user's settings is via
  1632 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  1633 script.
  1634 
  1635 * Multithreading.max_threads := 0 refers to the number of actual CPU
  1636 cores of the underlying machine, which is a good starting point for
  1637 optimal performance tuning.  The corresponding usedir option -M allows
  1638 "max" as an alias for "0".  WARNING: does not work on certain versions
  1639 of Mac OS (with Poly/ML 5.1).
  1640 
  1641 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  1642 adverse effect of Isabelle flooding interactive front-ends (notably
  1643 ProofGeneral / XEmacs).
  1644 
  1645 
  1646 
  1647 New in Isabelle2007 (November 2007)
  1648 -----------------------------------
  1649 
  1650 *** General ***
  1651 
  1652 * More uniform information about legacy features, notably a
  1653 warning/error of "Legacy feature: ...", depending on the state of the
  1654 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  1655 legacy features will disappear eventually.
  1656 
  1657 * Theory syntax: the header format ``theory A = B + C:'' has been
  1658 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  1659 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  1660 
  1661 * Theory syntax: the old non-Isar theory file format has been
  1662 discontinued altogether.  Note that ML proof scripts may still be used
  1663 with Isar theories; migration is usually quite simple with the ML
  1664 function use_legacy_bindings.  INCOMPATIBILITY.
  1665 
  1666 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  1667 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  1668 quotes.
  1669 
  1670 * Theory loader: be more serious about observing the static theory
  1671 header specifications (including optional directories), but not the
  1672 accidental file locations of previously successful loads.  The strict
  1673 update policy of former update_thy is now already performed by
  1674 use_thy, so the former has been removed; use_thys updates several
  1675 theories simultaneously, just as 'imports' within a theory header
  1676 specification, but without merging the results.  Potential
  1677 INCOMPATIBILITY: may need to refine theory headers and commands
  1678 ROOT.ML which depend on load order.
  1679 
  1680 * Theory loader: optional support for content-based file
  1681 identification, instead of the traditional scheme of full physical
  1682 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  1683 (cf. the system manual).  The new scheme allows to work with
  1684 non-finished theories in persistent session images, such that source
  1685 files may be moved later on without requiring reloads.
  1686 
  1687 * Theory loader: old-style ML proof scripts being *attached* to a thy
  1688 file (with the same base name as the theory) are considered a legacy
  1689 feature, which will disappear eventually. Even now, the theory loader
  1690 no longer maintains dependencies on such files.
  1691 
  1692 * Syntax: the scope for resolving ambiguities via type-inference is
  1693 now limited to individual terms, instead of whole simultaneous
  1694 specifications as before. This greatly reduces the complexity of the
  1695 syntax module and improves flexibility by separating parsing and
  1696 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  1697 'fixes' etc.) are required in rare situations.
  1698 
  1699 * Syntax: constants introduced by new-style packages ('definition',
  1700 'abbreviation' etc.) are passed through the syntax module in
  1701 ``authentic mode''. This means that associated mixfix annotations
  1702 really stick to such constants, independently of potential name space
  1703 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  1704 trees are represented slightly differently, may need to adapt syntax
  1705 translations accordingly. Use CONST marker in 'translations' and
  1706 @{const_syntax} antiquotation in 'parse_translation' etc.
  1707 
  1708 * Legacy goal package: reduced interface to the bare minimum required
  1709 to keep existing proof scripts running.  Most other user-level
  1710 functions are now part of the OldGoals structure, which is *not* open
  1711 by default (consider isatool expandshort before open OldGoals).
  1712 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  1713 these tend to cause confusion about the actual goal (!) context being
  1714 used here, which is not necessarily the same as the_context().
  1715 
  1716 * Command 'find_theorems': supports "*" wild-card in "name:"
  1717 criterion; "with_dups" option.  Certain ProofGeneral versions might
  1718 support a specific search form (see ProofGeneral/CHANGES).
  1719 
  1720 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  1721 by default, which means that "prems" (and also "fixed variables") are
  1722 suppressed from proof state output.  Note that the ProofGeneral
  1723 settings mechanism allows to change and save options persistently, but
  1724 older versions of Isabelle will fail to start up if a negative prems
  1725 limit is imposed.
  1726 
  1727 * Local theory targets may be specified by non-nested blocks of
  1728 ``context/locale/class ... begin'' followed by ``end''.  The body may
  1729 contain definitions, theorems etc., including any derived mechanism
  1730 that has been implemented on top of these primitives.  This concept
  1731 generalizes the existing ``theorem (in ...)'' towards more versatility
  1732 and scalability.
  1733 
  1734 * Proof General interface: proper undo of final 'end' command;
  1735 discontinued Isabelle/classic mode (ML proof scripts).
  1736 
  1737 
  1738 *** Document preparation ***
  1739 
  1740 * Added antiquotation @{theory name} which prints the given name,
  1741 after checking that it refers to a valid ancestor theory in the
  1742 current context.
  1743 
  1744 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  1745 check the given source text as ML type/structure, printing verbatim.
  1746 
  1747 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  1748 "c args == rhs" given in the current context.  (Any number of
  1749 arguments may be given on the LHS.)
  1750 
  1751 
  1752 *** Pure ***
  1753 
  1754 * The 'class' package offers a combination of axclass and locale to
  1755 achieve Haskell-like type classes in Isabelle.  Definitions and
  1756 theorems within a class context produce both relative results (with
  1757 implicit parameters according to the locale context), and polymorphic
  1758 constants with qualified polymorphism (according to the class
  1759 context).  Within the body context of a 'class' target, a separate
  1760 syntax layer ("user space type system") takes care of converting
  1761 between global polymorphic consts and internal locale representation.
  1762 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  1763 "isatool doc classes" provides a tutorial.
  1764 
  1765 * Generic code generator framework allows to generate executable
  1766 code for ML and Haskell (including Isabelle classes).  A short usage
  1767 sketch:
  1768 
  1769     internal compilation:
  1770         export_code <list of constants (term syntax)> in SML
  1771     writing SML code to a file:
  1772         export_code <list of constants (term syntax)> in SML <filename>
  1773     writing OCaml code to a file:
  1774         export_code <list of constants (term syntax)> in OCaml <filename>
  1775     writing Haskell code to a bunch of files:
  1776         export_code <list of constants (term syntax)> in Haskell <filename>
  1777 
  1778     evaluating closed propositions to True/False using code generation:
  1779         method ``eval''
  1780 
  1781 Reasonable default setup of framework in HOL.
  1782 
  1783 Theorem attributs for selecting and transforming function equations theorems:
  1784 
  1785     [code fun]:        select a theorem as function equation for a specific constant
  1786     [code fun del]:    deselect a theorem as function equation for a specific constant
  1787     [code inline]:     select an equation theorem for unfolding (inlining) in place
  1788     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  1789 
  1790 User-defined serializations (target in {SML, OCaml, Haskell}):
  1791 
  1792     code_const <and-list of constants (term syntax)>
  1793       {(target) <and-list of const target syntax>}+
  1794 
  1795     code_type <and-list of type constructors>
  1796       {(target) <and-list of type target syntax>}+
  1797 
  1798     code_instance <and-list of instances>
  1799       {(target)}+
  1800         where instance ::= <type constructor> :: <class>
  1801 
  1802     code_class <and_list of classes>
  1803       {(target) <and-list of class target syntax>}+
  1804         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  1805 
  1806 code_instance and code_class only are effective to target Haskell.
  1807 
  1808 For example usage see src/HOL/ex/Codegenerator.thy and
  1809 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  1810 generation from Isabelle/HOL theories is available via "isatool doc
  1811 codegen".
  1812 
  1813 * Code generator: consts in 'consts_code' Isar commands are now
  1814 referred to by usual term syntax (including optional type
  1815 annotations).
  1816 
  1817 * Command 'no_translations' removes translation rules from theory
  1818 syntax.
  1819 
  1820 * Overloaded definitions are now actually checked for acyclic
  1821 dependencies.  The overloading scheme is slightly more general than
  1822 that of Haskell98, although Isabelle does not demand an exact
  1823 correspondence to type class and instance declarations.
  1824 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  1825 exotic versions of overloading -- at the discretion of the user!
  1826 
  1827 Polymorphic constants are represented via type arguments, i.e. the
  1828 instantiation that matches an instance against the most general
  1829 declaration given in the signature.  For example, with the declaration
  1830 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  1831 as c(nat).  Overloading is essentially simultaneous structural
  1832 recursion over such type arguments.  Incomplete specification patterns
  1833 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  1834 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  1835 Command 'print_theory' outputs the normalized system of recursive
  1836 equations, see section "definitions".
  1837 
  1838 * Configuration options are maintained within the theory or proof
  1839 context (with name and type bool/int/string), providing a very simple
  1840 interface to a poor-man's version of general context data.  Tools may
  1841 declare options in ML (e.g. using Attrib.config_int) and then refer to
  1842 these values using Config.get etc.  Users may change options via an
  1843 associated attribute of the same name.  This form of context
  1844 declaration works particularly well with commands 'declare' or
  1845 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  1846 very easy to avoid global references, which would not observe Isar
  1847 toplevel undo/redo and fail to work with multithreading.
  1848 
  1849 Various global ML references of Pure and HOL have been turned into
  1850 configuration options:
  1851 
  1852   Unify.search_bound		unify_search_bound
  1853   Unify.trace_bound		unify_trace_bound
  1854   Unify.trace_simp		unify_trace_simp
  1855   Unify.trace_types		unify_trace_types
  1856   Simplifier.simp_depth_limit	simp_depth_limit
  1857   Blast.depth_limit		blast_depth_limit
  1858   DatatypeProp.dtK		datatype_distinctness_limit
  1859   fast_arith_neq_limit  	fast_arith_neq_limit
  1860   fast_arith_split_limit	fast_arith_split_limit
  1861 
  1862 * Named collections of theorems may be easily installed as context
  1863 data using the functor NamedThmsFun (see also
  1864 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  1865 attributes; there is also a toplevel print command.  This facility is
  1866 just a common case of general context data, which is the preferred way
  1867 for anything more complex than just a list of facts in canonical
  1868 order.
  1869 
  1870 * Isar: command 'declaration' augments a local theory by generic
  1871 declaration functions written in ML.  This enables arbitrary content
  1872 being added to the context, depending on a morphism that tells the
  1873 difference of the original declaration context wrt. the application
  1874 context encountered later on.
  1875 
  1876 * Isar: proper interfaces for simplification procedures.  Command
  1877 'simproc_setup' declares named simprocs (with match patterns, and body
  1878 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  1879 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  1880 
  1881 * Isar: an extra pair of brackets around attribute declarations
  1882 abbreviates a theorem reference involving an internal dummy fact,
  1883 which will be ignored later --- only the effect of the attribute on
  1884 the background context will persist.  This form of in-place
  1885 declarations is particularly useful with commands like 'declare' and
  1886 'using', for example ``have A using [[simproc a]] by simp''.
  1887 
  1888 * Isar: method "assumption" (and implicit closing of subproofs) now
  1889 takes simple non-atomic goal assumptions into account: after applying
  1890 an assumption as a rule the resulting subgoals are solved by atomic
  1891 assumption steps.  This is particularly useful to finish 'obtain'
  1892 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  1893 without referring to the original premise "!!x. P x ==> thesis" in the
  1894 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  1895 more permissive.
  1896 
  1897 * Isar: implicit use of prems from the Isar proof context is
  1898 considered a legacy feature.  Common applications like ``have A .''
  1899 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  1900 referencing facts explicitly here improves readability and
  1901 maintainability of proof texts.
  1902 
  1903 * Isar: improper proof element 'guess' is like 'obtain', but derives
  1904 the obtained context from the course of reasoning!  For example:
  1905 
  1906   assume "EX x y. A x & B y"   -- "any previous fact"
  1907   then guess x and y by clarify
  1908 
  1909 This technique is potentially adventurous, depending on the facts and
  1910 proof tools being involved here.
  1911 
  1912 * Isar: known facts from the proof context may be specified as literal
  1913 propositions, using ASCII back-quote syntax.  This works wherever
  1914 named facts used to be allowed so far, in proof commands, proof
  1915 methods, attributes etc.  Literal facts are retrieved from the context
  1916 according to unification of type and term parameters.  For example,
  1917 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  1918 theorems in the current context, then these are valid literal facts:
  1919 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  1920 
  1921 There is also a proof method "fact" which does the same composition
  1922 for explicit goal states, e.g. the following proof texts coincide with
  1923 certain special cases of literal facts:
  1924 
  1925   have "A" by fact                 ==  note `A`
  1926   have "A ==> B" by fact           ==  note `A ==> B`
  1927   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  1928   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  1929 
  1930 * Isar: ":" (colon) is no longer a symbolic identifier character in
  1931 outer syntax.  Thus symbolic identifiers may be used without
  1932 additional white space in declarations like this: ``assume *: A''.
  1933 
  1934 * Isar: 'print_facts' prints all local facts of the current context,
  1935 both named and unnamed ones.
  1936 
  1937 * Isar: 'def' now admits simultaneous definitions, e.g.:
  1938 
  1939   def x == "t" and y == "u"
  1940 
  1941 * Isar: added command 'unfolding', which is structurally similar to
  1942 'using', but affects both the goal state and facts by unfolding given
  1943 rewrite rules.  Thus many occurrences of the 'unfold' method or
  1944 'unfolded' attribute may be replaced by first-class proof text.
  1945 
  1946 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  1947 and command 'unfolding' now all support object-level equalities
  1948 (potentially conditional).  The underlying notion of rewrite rule is
  1949 analogous to the 'rule_format' attribute, but *not* that of the
  1950 Simplifier (which is usually more generous).
  1951 
  1952 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  1953 premises of a theorem by n. Useful in conjunction with drule.
  1954 
  1955 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  1956 method expression within a sandbox consisting of the first N
  1957 sub-goals, which need to exist.  For example, ``simp_all [3]''
  1958 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  1959 simplifies all new goals that emerge from applying rule foo to the
  1960 originally first one.
  1961 
  1962 * Isar: schematic goals are no longer restricted to higher-order
  1963 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  1964 expected.
  1965 
  1966 * Isar: the conclusion of a long theorem statement is now either
  1967 'shows' (a simultaneous conjunction, as before), or 'obtains'
  1968 (essentially a disjunction of cases with local parameters and
  1969 assumptions).  The latter allows to express general elimination rules
  1970 adequately; in this notation common elimination rules look like this:
  1971 
  1972   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  1973     assumes "EX x. P x"
  1974     obtains x where "P x"
  1975 
  1976   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  1977     assumes "A & B"
  1978     obtains A and B
  1979 
  1980   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  1981     assumes "A | B"
  1982     obtains
  1983       A
  1984     | B
  1985 
  1986 The subsequent classical rules even refer to the formal "thesis"
  1987 explicitly:
  1988 
  1989   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  1990     obtains "~ thesis"
  1991 
  1992   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  1993     obtains "thesis ==> something"
  1994 
  1995 The actual proof of an 'obtains' statement is analogous to that of the
  1996 Isar proof element 'obtain', only that there may be several cases.
  1997 Optional case names may be specified in parentheses; these will be
  1998 available both in the present proof and as annotations in the
  1999 resulting rule, for later use with the 'cases' method (cf. attribute
  2000 case_names).
  2001 
  2002 * Isar: the assumptions of a long theorem statement are available as
  2003 "assms" fact in the proof context.  This is more appropriate than the
  2004 (historical) "prems", which refers to all assumptions of the current
  2005 context, including those from the target locale, proof body etc.
  2006 
  2007 * Isar: 'print_statement' prints theorems from the current theory or
  2008 proof context in long statement form, according to the syntax of a
  2009 top-level lemma.
  2010 
  2011 * Isar: 'obtain' takes an optional case name for the local context
  2012 introduction rule (default "that").
  2013 
  2014 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  2015 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  2016 to occur.
  2017 
  2018 * Pure: syntax "CONST name" produces a fully internalized constant
  2019 according to the current context.  This is particularly useful for
  2020 syntax translations that should refer to internal constant
  2021 representations independently of name spaces.
  2022 
  2023 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  2024 instead of "FOO ". This allows multiple binder declarations to coexist
  2025 in the same context.  INCOMPATIBILITY.
  2026 
  2027 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  2028 primitive that also works in a locale context (both for constants and
  2029 fixed variables). Type declaration and internal syntactic representation
  2030 of given constants retrieved from the context. Likewise, the
  2031 'no_notation' command allows to remove given syntax annotations from the
  2032 current context.
  2033 
  2034 * Isar/locales: new derived specification elements 'axiomatization',
  2035 'definition', 'abbreviation', which support type-inference, admit
  2036 object-level specifications (equality, equivalence).  See also the
  2037 isar-ref manual.  Examples:
  2038 
  2039   axiomatization
  2040     eq  (infix "===" 50) where
  2041     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  2042 
  2043   definition "f x y = x + y + 1"
  2044   definition g where "g x = f x x"
  2045 
  2046   abbreviation
  2047     neq  (infix "=!=" 50) where
  2048     "x =!= y == ~ (x === y)"
  2049 
  2050 These specifications may be also used in a locale context.  Then the
  2051 constants being introduced depend on certain fixed parameters, and the
  2052 constant name is qualified by the locale base name.  An internal
  2053 abbreviation takes care for convenient input and output, making the
  2054 parameters implicit and using the original short name.  See also
  2055 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  2056 entities from a monomorphic theory.
  2057 
  2058 Presently, abbreviations are only available 'in' a target locale, but
  2059 not inherited by general import expressions.  Also note that
  2060 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  2061 'translations' in common applications.  The "no_abbrevs" print mode
  2062 prevents folding of abbreviations in term output.
  2063 
  2064 Concrete syntax is attached to specified constants in internal form,
  2065 independently of name spaces.  The parse tree representation is
  2066 slightly different -- use 'notation' instead of raw 'syntax', and
  2067 'translations' with explicit "CONST" markup to accommodate this.
  2068 
  2069 * Pure/Isar: unified syntax for new-style specification mechanisms
  2070 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  2071 full type inference and dummy patterns ("_").  For example:
  2072 
  2073   definition "K x _ = x"
  2074 
  2075   inductive conj for A B
  2076   where "A ==> B ==> conj A B"
  2077 
  2078 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  2079 the current context.  Print mode "no_abbrevs" prevents inversion of
  2080 abbreviations on output.
  2081 
  2082 * Isar/locales: improved parameter handling: use of locales "var" and
  2083 "struct" no longer necessary; - parameter renamings are no longer
  2084 required to be injective.  For example, this allows to define
  2085 endomorphisms as locale endom = homom mult mult h.
  2086 
  2087 * Isar/locales: changed the way locales with predicates are defined.
  2088 Instead of accumulating the specification, the imported expression is
  2089 now an interpretation.  INCOMPATIBILITY: different normal form of
  2090 locale expressions.  In particular, in interpretations of locales with
  2091 predicates, goals repesenting already interpreted fragments are not
  2092 removed automatically.  Use methods `intro_locales' and
  2093 `unfold_locales'; see below.
  2094 
  2095 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  2096 provide backward reasoning on locales predicates.  The methods are
  2097 aware of interpretations and discharge corresponding goals.
  2098 `intro_locales' is less aggressive then `unfold_locales' and does not
  2099 unfold predicates to assumptions.
  2100 
  2101 * Isar/locales: the order in which locale fragments are accumulated
  2102 has changed.  This enables to override declarations from fragments due
  2103 to interpretations -- for example, unwanted simp rules.
  2104 
  2105 * Isar/locales: interpretation in theories and proof contexts has been
  2106 extended.  One may now specify (and prove) equations, which are
  2107 unfolded in interpreted theorems.  This is useful for replacing
  2108 defined concepts (constants depending on locale parameters) by
  2109 concepts already existing in the target context.  Example:
  2110 
  2111   interpretation partial_order ["op <= :: [int, int] => bool"]
  2112     where "partial_order.less (op <=) (x::int) y = (x < y)"
  2113 
  2114 Typically, the constant `partial_order.less' is created by a
  2115 definition specification element in the context of locale
  2116 partial_order.
  2117 
  2118 * Method "induct": improved internal context management to support
  2119 local fixes and defines on-the-fly. Thus explicit meta-level
  2120 connectives !!  and ==> are rarely required anymore in inductive goals
  2121 (using object-logic connectives for this purpose has been long
  2122 obsolete anyway). Common proof patterns are explained in
  2123 src/HOL/Induct/Common_Patterns.thy, see also
  2124 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  2125 examples.
  2126 
  2127 * Method "induct": improved handling of simultaneous goals. Instead of
  2128 introducing object-level conjunction, the statement is now split into
  2129 several conclusions, while the corresponding symbolic cases are nested
  2130 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  2131 see src/HOL/Induct/Common_Patterns.thy, for example.
  2132 
  2133 * Method "induct": mutual induction rules are now specified as a list
  2134 of rule sharing the same induction cases. HOL packages usually provide
  2135 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  2136 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  2137 mutual induction rules differently, i.e. like this:
  2138 
  2139   (induct rule: foo_bar.inducts)
  2140   (induct set: foo bar)
  2141   (induct pred: foo bar)
  2142   (induct type: foo bar)
  2143 
  2144 The ML function ProjectRule.projections turns old-style rules into the
  2145 new format.
  2146 
  2147 * Method "coinduct": dual of induction, see
  2148 src/HOL/Library/Coinductive_List.thy for various examples.
  2149 
  2150 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  2151 considered a legacy feature.
  2152 
  2153 * Attribute "symmetric" produces result with standardized schematic
  2154 variables (index 0).  Potential INCOMPATIBILITY.
  2155 
  2156 * Simplifier: by default the simplifier trace only shows top level
  2157 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  2158 default. Thus there is less danger of being flooded by the trace. The
  2159 trace indicates where parts have been suppressed.
  2160   
  2161 * Provers/classical: removed obsolete classical version of elim_format
  2162 attribute; classical elim/dest rules are now treated uniformly when
  2163 manipulating the claset.
  2164 
  2165 * Provers/classical: stricter checks to ensure that supplied intro,
  2166 dest and elim rules are well-formed; dest and elim rules must have at
  2167 least one premise.
  2168 
  2169 * Provers/classical: attributes dest/elim/intro take an optional
  2170 weight argument for the rule (just as the Pure versions).  Weights are
  2171 ignored by automated tools, but determine the search order of single
  2172 rule steps.
  2173 
  2174 * Syntax: input syntax now supports dummy variable binding "%_. b",
  2175 where the body does not mention the bound variable.  Note that dummy
  2176 patterns implicitly depend on their context of bounds, which makes
  2177 "{_. _}" match any set comprehension as expected.  Potential
  2178 INCOMPATIBILITY -- parse translations need to cope with syntactic
  2179 constant "_idtdummy" in the binding position.
  2180 
  2181 * Syntax: removed obsolete syntactic constant "_K" and its associated
  2182 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  2183 for example "A -> B" => "Pi A (%_. B)".
  2184 
  2185 * Pure: 'class_deps' command visualizes the subclass relation, using
  2186 the graph browser tool.
  2187 
  2188 * Pure: 'print_theory' now suppresses certain internal declarations by
  2189 default; use '!' option for full details.
  2190 
  2191 
  2192 *** HOL ***
  2193 
  2194 * Method "metis" proves goals by applying the Metis general-purpose
  2195 resolution prover (see also http://gilith.com/software/metis/).
  2196 Examples are in the directory MetisExamples.  WARNING: the
  2197 Isabelle/HOL-Metis integration does not yet work properly with
  2198 multi-threading.
  2199   
  2200 * Command 'sledgehammer' invokes external automatic theorem provers as
  2201 background processes.  It generates calls to the "metis" method if
  2202 successful. These can be pasted into the proof.  Users do not have to
  2203 wait for the automatic provers to return.  WARNING: does not really
  2204 work with multi-threading.
  2205 
  2206 * New "auto_quickcheck" feature tests outermost goal statements for
  2207 potential counter-examples.  Controlled by ML references
  2208 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  2209 5000 milliseconds).  Fails silently if statements is outside of
  2210 executable fragment, or any other codgenerator problem occurs.
  2211 
  2212 * New constant "undefined" with axiom "undefined x = undefined".
  2213 
  2214 * Added class "HOL.eq", allowing for code generation with polymorphic
  2215 equality.
  2216 
  2217 * Some renaming of class constants due to canonical name prefixing in
  2218 the new 'class' package:
  2219 
  2220     HOL.abs ~> HOL.abs_class.abs
  2221     HOL.divide ~> HOL.divide_class.divide
  2222     0 ~> HOL.zero_class.zero
  2223     1 ~> HOL.one_class.one
  2224     op + ~> HOL.plus_class.plus
  2225     op - ~> HOL.minus_class.minus
  2226     uminus ~> HOL.minus_class.uminus
  2227     op * ~> HOL.times_class.times
  2228     op < ~> HOL.ord_class.less
  2229     op <= > HOL.ord_class.less_eq
  2230     Nat.power ~> Power.power_class.power
  2231     Nat.size ~> Nat.size_class.size
  2232     Numeral.number_of ~> Numeral.number_class.number_of
  2233     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  2234     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  2235     Orderings.min ~> Orderings.ord_class.min
  2236     Orderings.max ~> Orderings.ord_class.max
  2237     Divides.op div ~> Divides.div_class.div
  2238     Divides.op mod ~> Divides.div_class.mod
  2239     Divides.op dvd ~> Divides.div_class.dvd
  2240 
  2241 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  2242 
  2243 a) User-defined constants using any of the names "plus", "minus",
  2244 "times", "less" or "less_eq". The standard syntax translations for
  2245 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  2246 names.
  2247 
  2248 b) Variables named "plus", "minus", "times", "less", "less_eq"
  2249 INCOMPATIBILITY: use more specific names.
  2250 
  2251 c) Permutative equations (e.g. "a + b = b + a")
  2252 Since the change of names also changes the order of terms, permutative
  2253 rewrite rules may get applied in a different order. Experience shows
  2254 that this is rarely the case (only two adaptions in the whole Isabelle
  2255 distribution).  INCOMPATIBILITY: rewrite proofs
  2256 
  2257 d) ML code directly refering to constant names
  2258 This in general only affects hand-written proof tactics, simprocs and
  2259 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  2260 Consider using @{const_name} antiquotation.
  2261 
  2262 * New class "default" with associated constant "default".
  2263 
  2264 * Function "sgn" is now overloaded and available on int, real, complex
  2265 (and other numeric types), using class "sgn".  Two possible defs of
  2266 sgn are given as equational assumptions in the classes sgn_if and
  2267 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  2268 INCOMPATIBILITY.
  2269 
  2270 * Locale "partial_order" now unified with class "order" (cf. theory
  2271 Orderings), added parameter "less".  INCOMPATIBILITY.
  2272 
  2273 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  2274 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  2275 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  2276 
  2277 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  2278 changed order of proof goals in instance proofs.
  2279 
  2280 * The transitivity reasoner for partial and linear orders is set up
  2281 for classes "order" and "linorder".  Instances of the reasoner are available
  2282 in all contexts importing or interpreting the corresponding locales.
  2283 Method "order" invokes the reasoner separately; the reasoner
  2284 is also integrated with the Simplifier as a solver.  Diagnostic
  2285 command 'print_orders' shows the available instances of the reasoner
  2286 in the current context.
  2287 
  2288 * Localized monotonicity predicate in theory "Orderings"; integrated
  2289 lemmas max_of_mono and min_of_mono with this predicate.
  2290 INCOMPATIBILITY.
  2291 
  2292 * Formulation of theorem "dense" changed slightly due to integration
  2293 with new class dense_linear_order.
  2294 
  2295 * Uniform lattice theory development in HOL.
  2296 
  2297     constants "meet" and "join" now named "inf" and "sup"
  2298     constant "Meet" now named "Inf"
  2299 
  2300     classes "meet_semilorder" and "join_semilorder" now named
  2301       "lower_semilattice" and "upper_semilattice"
  2302     class "lorder" now named "lattice"
  2303     class "comp_lat" now named "complete_lattice"
  2304 
  2305     Instantiation of lattice classes allows explicit definitions
  2306     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  2307 
  2308   INCOMPATIBILITY.  Theorem renames:
  2309 
  2310     meet_left_le            ~> inf_le1
  2311     meet_right_le           ~> inf_le2
  2312     join_left_le            ~> sup_ge1
  2313     join_right_le           ~> sup_ge2
  2314     meet_join_le            ~> inf_sup_ord
  2315     le_meetI                ~> le_infI
  2316     join_leI                ~> le_supI
  2317     le_meet                 ~> le_inf_iff
  2318     le_join                 ~> ge_sup_conv
  2319     meet_idempotent         ~> inf_idem
  2320     join_idempotent         ~> sup_idem
  2321     meet_comm               ~> inf_commute
  2322     join_comm               ~> sup_commute
  2323     meet_leI1               ~> le_infI1
  2324     meet_leI2               ~> le_infI2
  2325     le_joinI1               ~> le_supI1
  2326     le_joinI2               ~> le_supI2
  2327     meet_assoc              ~> inf_assoc
  2328     join_assoc              ~> sup_assoc
  2329     meet_left_comm          ~> inf_left_commute
  2330     meet_left_idempotent    ~> inf_left_idem
  2331     join_left_comm          ~> sup_left_commute
  2332     join_left_idempotent    ~> sup_left_idem
  2333     meet_aci                ~> inf_aci
  2334     join_aci                ~> sup_aci
  2335     le_def_meet             ~> le_iff_inf
  2336     le_def_join             ~> le_iff_sup
  2337     join_absorp2            ~> sup_absorb2
  2338     join_absorp1            ~> sup_absorb1
  2339     meet_absorp1            ~> inf_absorb1
  2340     meet_absorp2            ~> inf_absorb2
  2341     meet_join_absorp        ~> inf_sup_absorb
  2342     join_meet_absorp        ~> sup_inf_absorb
  2343     distrib_join_le         ~> distrib_sup_le
  2344     distrib_meet_le         ~> distrib_inf_le
  2345 
  2346     add_meet_distrib_left   ~> add_inf_distrib_left
  2347     add_join_distrib_left   ~> add_sup_distrib_left
  2348     is_join_neg_meet        ~> is_join_neg_inf
  2349     is_meet_neg_join        ~> is_meet_neg_sup
  2350     add_meet_distrib_right  ~> add_inf_distrib_right
  2351     add_join_distrib_right  ~> add_sup_distrib_right
  2352     add_meet_join_distribs  ~> add_sup_inf_distribs
  2353     join_eq_neg_meet        ~> sup_eq_neg_inf
  2354     meet_eq_neg_join        ~> inf_eq_neg_sup
  2355     add_eq_meet_join        ~> add_eq_inf_sup
  2356     meet_0_imp_0            ~> inf_0_imp_0
  2357     join_0_imp_0            ~> sup_0_imp_0
  2358     meet_0_eq_0             ~> inf_0_eq_0
  2359     join_0_eq_0             ~> sup_0_eq_0
  2360     neg_meet_eq_join        ~> neg_inf_eq_sup
  2361     neg_join_eq_meet        ~> neg_sup_eq_inf
  2362     join_eq_if              ~> sup_eq_if
  2363 
  2364     mono_meet               ~> mono_inf
  2365     mono_join               ~> mono_sup
  2366     meet_bool_eq            ~> inf_bool_eq
  2367     join_bool_eq            ~> sup_bool_eq
  2368     meet_fun_eq             ~> inf_fun_eq
  2369     join_fun_eq             ~> sup_fun_eq
  2370     meet_set_eq             ~> inf_set_eq
  2371     join_set_eq             ~> sup_set_eq
  2372     meet1_iff               ~> inf1_iff
  2373     meet2_iff               ~> inf2_iff
  2374     meet1I                  ~> inf1I
  2375     meet2I                  ~> inf2I
  2376     meet1D1                 ~> inf1D1
  2377     meet2D1                 ~> inf2D1
  2378     meet1D2                 ~> inf1D2
  2379     meet2D2                 ~> inf2D2
  2380     meet1E                  ~> inf1E
  2381     meet2E                  ~> inf2E
  2382     join1_iff               ~> sup1_iff
  2383     join2_iff               ~> sup2_iff
  2384     join1I1                 ~> sup1I1
  2385     join2I1                 ~> sup2I1
  2386     join1I1                 ~> sup1I1
  2387     join2I2                 ~> sup1I2
  2388     join1CI                 ~> sup1CI
  2389     join2CI                 ~> sup2CI
  2390     join1E                  ~> sup1E
  2391     join2E                  ~> sup2E
  2392 
  2393     is_meet_Meet            ~> is_meet_Inf
  2394     Meet_bool_def           ~> Inf_bool_def
  2395     Meet_fun_def            ~> Inf_fun_def
  2396     Meet_greatest           ~> Inf_greatest
  2397     Meet_lower              ~> Inf_lower
  2398     Meet_set_def            ~> Inf_set_def
  2399 
  2400     Sup_def                 ~> Sup_Inf
  2401     Sup_bool_eq             ~> Sup_bool_def
  2402     Sup_fun_eq              ~> Sup_fun_def
  2403     Sup_set_eq              ~> Sup_set_def
  2404 
  2405     listsp_meetI            ~> listsp_infI
  2406     listsp_meet_eq          ~> listsp_inf_eq
  2407 
  2408     meet_min                ~> inf_min
  2409     join_max                ~> sup_max
  2410 
  2411 * Added syntactic class "size"; overloaded constant "size" now has
  2412 type "'a::size ==> bool"
  2413 
  2414 * Internal reorganisation of `size' of datatypes: size theorems
  2415 "foo.size" are no longer subsumed by "foo.simps" (but are still
  2416 simplification rules by default!); theorems "prod.size" now named
  2417 "*.size".
  2418 
  2419 * Class "div" now inherits from class "times" rather than "type".
  2420 INCOMPATIBILITY.
  2421 
  2422 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  2423 Linorder etc.  have disappeared; operations defined in terms of
  2424 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  2425 
  2426 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  2427 
  2428 * HOL-Word: New extensive library and type for generic, fixed size
  2429 machine words, with arithemtic, bit-wise, shifting and rotating
  2430 operations, reflection into int, nat, and bool lists, automation for
  2431 linear arithmetic (by automatic reflection into nat or int), including
  2432 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  2433 arithmetic type classes, supporting automatic simplification of
  2434 numerals on all operations.
  2435 
  2436 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  2437 
  2438 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  2439 
  2440 * Code generator library theories:
  2441   - Code_Integer represents HOL integers by big integer literals in target
  2442     languages.
  2443   - Code_Char represents HOL characters by character literals in target
  2444     languages.
  2445   - Code_Char_chr like Code_Char, but also offers treatment of character
  2446     codes; includes Code_Integer.
  2447   - Executable_Set allows to generate code for finite sets using lists.
  2448   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  2449     denominator).
  2450   - Executable_Real implements a subset of real numbers, namly those
  2451     representable by rational numbers.
  2452   - Efficient_Nat implements natural numbers by integers, which in general will
  2453     result in higher efficency; pattern matching with 0/Suc is eliminated;
  2454     includes Code_Integer.
  2455   - Code_Index provides an additional datatype index which is mapped to
  2456     target-language built-in integers.
  2457   - Code_Message provides an additional datatype message_string which is isomorphic to
  2458     strings; messages are mapped to target-language strings.
  2459 
  2460 * New package for inductive predicates
  2461 
  2462   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  2463 
  2464     inductive
  2465       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2466       for z_1 :: U_1 and ... and z_n :: U_m
  2467     where
  2468       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2469     | ...
  2470 
  2471   with full support for type-inference, rather than
  2472 
  2473     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2474 
  2475     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2476     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2477 
  2478     inductive "s z_1 ... z_m"
  2479     intros
  2480       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2481       ...
  2482 
  2483   For backward compatibility, there is a wrapper allowing inductive
  2484   sets to be defined with the new package via
  2485 
  2486     inductive_set
  2487       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2488       for z_1 :: U_1 and ... and z_n :: U_m
  2489     where
  2490       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  2491     | ...
  2492 
  2493   or
  2494 
  2495     inductive_set
  2496       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  2497       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  2498       for z_1 :: U_1 and ... and z_n :: U_m
  2499     where
  2500       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  2501     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  2502     | ...
  2503 
  2504   if the additional syntax "p ..." is required.
  2505 
  2506   Numerous examples can be found in the subdirectories src/HOL/Auth,
  2507   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  2508 
  2509   INCOMPATIBILITIES:
  2510 
  2511   - Since declaration and definition of inductive sets or predicates
  2512     is no longer separated, abbreviations involving the newly
  2513     introduced sets or predicates must be specified together with the
  2514     introduction rules after the 'where' keyword (see above), rather
  2515     than before the actual inductive definition.
  2516 
  2517   - The variables in induction and elimination rules are now
  2518     quantified in the order of their occurrence in the introduction
  2519     rules, rather than in alphabetical order. Since this may break
  2520     some proofs, these proofs either have to be repaired, e.g. by
  2521     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  2522     statements of the form
  2523 
  2524       case (rule_i a_i_1 ... a_i_{k_i})
  2525 
  2526     or the old order of quantification has to be restored by explicitly adding
  2527     meta-level quantifiers in the introduction rules, i.e.
  2528 
  2529       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  2530 
  2531   - The format of the elimination rules is now
  2532 
  2533       p z_1 ... z_m x_1 ... x_n ==>
  2534         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2535         ==> ... ==> P
  2536 
  2537     for predicates and
  2538 
  2539       (x_1, ..., x_n) : s z_1 ... z_m ==>
  2540         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  2541         ==> ... ==> P
  2542 
  2543     for sets rather than
  2544 
  2545       x : s z_1 ... z_m ==>
  2546         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  2547         ==> ... ==> P
  2548 
  2549     This may require terms in goals to be expanded to n-tuples
  2550     (e.g. using case_tac or simplification with the split_paired_all
  2551     rule) before the above elimination rule is applicable.
  2552 
  2553   - The elimination or case analysis rules for (mutually) inductive
  2554     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  2555     list of rules "p_1_..._p_k.elims" is no longer available.
  2556 
  2557 * New package "function"/"fun" for general recursive functions,
  2558 supporting mutual and nested recursion, definitions in local contexts,
  2559 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  2560 for small examples, and the separate tutorial on the function
  2561 package. The old recdef "package" is still available as before, but
  2562 users are encouraged to use the new package.
  2563 
  2564 * Method "lexicographic_order" automatically synthesizes termination
  2565 relations as lexicographic combinations of size measures. 
  2566 
  2567 * Case-expressions allow arbitrary constructor-patterns (including
  2568 "_") and take their order into account, like in functional
  2569 programming.  Internally, this is translated into nested
  2570 case-expressions; missing cases are added and mapped to the predefined
  2571 constant "undefined". In complicated cases printing may no longer show
  2572 the original input but the internal form. Lambda-abstractions allow
  2573 the same form of pattern matching: "% pat1 => e1 | ..." is an
  2574 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  2575 variable.
  2576 
  2577 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  2578 is an abbreviation for "of_nat :: nat => int". The simplification
  2579 rules for "of_nat" have been changed to work like "int" did
  2580 previously.  Potential INCOMPATIBILITY:
  2581   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  2582   - of_nat_diff and of_nat_mult are no longer default simp rules
  2583 
  2584 * Method "algebra" solves polynomial equations over (semi)rings using
  2585 Groebner bases. The (semi)ring structure is defined by locales and the
  2586 tool setup depends on that generic context. Installing the method for
  2587 a specific type involves instantiating the locale and possibly adding
  2588 declarations for computation on the coefficients.  The method is
  2589 already instantiated for natural numbers and for the axiomatic class
  2590 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  2591 CALCULEMUS 2007 for the general principles underlying this
  2592 architecture of context-aware proof-tools.
  2593 
  2594 * Method "ferrack" implements quantifier elimination over
  2595 special-purpose dense linear orders using locales (analogous to
  2596 "algebra"). The method is already installed for class
  2597 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  2598 rat, etc.
  2599 
  2600 * Former constant "List.op @" now named "List.append".  Use ML
  2601 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  2602 circumvent possible incompatibilities when working on ML level.
  2603 
  2604 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  2605 
  2606 * New function listsum :: 'a list => 'a for arbitrary monoids.
  2607 Special syntax: "SUM x <- xs. f x" (and latex variants)
  2608 
  2609 * New syntax for Haskell-like list comprehension (input only), eg.
  2610 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  2611 
  2612 * The special syntax for function "filter" has changed from [x :
  2613 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  2614 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  2615 
  2616 * [a..b] is now defined for arbitrary linear orders.  It used to be
  2617 defined on nat only, as an abbreviation for [a..<Suc b]
  2618 INCOMPATIBILITY.
  2619 
  2620 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  2621 
  2622 * New functions "sorted" and "sort" in src/HOL/List.thy.
  2623 
  2624 * New lemma collection field_simps (an extension of ring_simps) for
  2625 manipulating (in)equations involving division. Multiplies with all
  2626 denominators that can be proved to be non-zero (in equations) or
  2627 positive/negative (in inequations).
  2628 
  2629 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  2630 have been improved and renamed to ring_simps, group_simps and
  2631 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  2632 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  2633 
  2634 * Theory Library/Commutative_Ring: switched from recdef to function
  2635 package; constants add, mul, pow now curried.  Infix syntax for
  2636 algebraic operations.
  2637 
  2638 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  2639 INCOMPATIBILITY.
  2640 
  2641 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  2642 INCOMPATIBILITY.
  2643 
  2644 * HOL/records: generalised field-update to take a function on the
  2645 field rather than the new value: r(|A := x|) is translated to A_update
  2646 (K x) r The K-combinator that is internally used is called K_record.
  2647 INCOMPATIBILITY: Usage of the plain update functions has to be
  2648 adapted.
  2649  
  2650 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  2651 * x = 0, which are required for a semiring.  Richer structures do not
  2652 inherit from semiring_0 anymore, because this property is a theorem
  2653 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  2654 there is more to prove, but this is mostly trivial.
  2655 
  2656 * Class "recpower" is generalized to arbitrary monoids, not just
  2657 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  2658 commutativity or semiring properties additionally.
  2659 
  2660 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  2661 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  2662 better use 'abbreviation'.
  2663 
  2664 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  2665 
  2666 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  2667 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  2668 significant changes for setting up numeral syntax for types:
  2669   - New constants Numeral.pred and Numeral.succ instead
  2670       of former Numeral.bin_pred and Numeral.bin_succ.
  2671   - Use integer operations instead of bin_add, bin_mult and so on.
  2672   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  2673   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  2674 
  2675 See src/HOL/Integ/IntArith.thy for an example setup.
  2676 
  2677 * Command 'normal_form' computes the normal form of a term that may
  2678 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  2679 produces ``[b, c, a]'' (without proof).  This command is suitable for
  2680 heavy-duty computations because the functions are compiled to ML
  2681 first.  Correspondingly, a method "normalization" is provided.  See
  2682 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  2683 
  2684 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  2685 25 like -->); output depends on the "iff" print_mode, the default is
  2686 "A = B" (with priority 50).
  2687 
  2688 * Relations less (<) and less_eq (<=) are also available on type bool.
  2689 Modified syntax to disallow nesting without explicit parentheses,
  2690 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  2691 INCOMPATIBILITY.
  2692 
  2693 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  2694 
  2695 * Relation composition operator "op O" now has precedence 75 and binds
  2696 stronger than union and intersection. INCOMPATIBILITY.
  2697 
  2698 * The old set interval syntax "{m..n(}" (and relatives) has been
  2699 removed.  Use "{m..<n}" (and relatives) instead.
  2700 
  2701 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  2702 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  2703 ``declare [[simproc del: neq]]''.
  2704 
  2705 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  2706 True/False.
  2707 
  2708 * Theorem Cons_eq_map_conv no longer declared as "simp".
  2709 
  2710 * Theorem setsum_mult renamed to setsum_right_distrib.
  2711 
  2712 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  2713 ``rule'' method.
  2714 
  2715 * Reimplemented methods "sat" and "satx", with several improvements:
  2716 goals no longer need to be stated as "<prems> ==> False", equivalences
  2717 (i.e. "=" on type bool) are handled, variable names of the form
  2718 "lit_<n>" are no longer reserved, significant speedup.
  2719 
  2720 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  2721 zChaff is still supported as well.
  2722 
  2723 * 'inductive' and 'datatype': provide projections of mutual rules,
  2724 bundled as foo_bar.inducts;
  2725 
  2726 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  2727 Library.
  2728 
  2729 * Library: moved theory Accessible_Part to main HOL.
  2730 
  2731 * Library: added theory Coinductive_List of potentially infinite lists
  2732 as greatest fixed-point.
  2733 
  2734 * Library: added theory AssocList which implements (finite) maps as
  2735 association lists.
  2736 
  2737 * Method "evaluation" solves goals (i.e. a boolean expression)
  2738 efficiently by compiling it to ML.  The goal is "proved" (via an
  2739 oracle) if it evaluates to True.
  2740 
  2741 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  2742 also when invoked by the simplifier.  This results in the Simplifier
  2743 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  2744 Configuration option fast_arith_split_limit=0 recovers the old
  2745 behavior.
  2746 
  2747 * Support for hex (0x20) and binary (0b1001) numerals.
  2748 
  2749 * New method: reify eqs (t), where eqs are equations for an
  2750 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  2751 parameter, computes a term s::'b and a list xs::'a list and proves the
  2752 theorem I xs s = t. This is also known as reification or quoting. The
  2753 resulting theorem is applied to the subgoal to substitute t with I xs
  2754 s.  If t is omitted, the subgoal itself is reified.
  2755 
  2756 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  2757 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  2758 where f is supposed to be a computable function (in the sense of code
  2759 generattion). The method uses reify to compute s and xs as above then
  2760 applies corr_thm and uses normalization by evaluation to "prove" f s =
  2761 r and finally gets the theorem t = r, which is again applied to the
  2762 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  2763 
  2764 * Reflection: Automatic reification now handels binding, an example is
  2765 available in src/HOL/ex/ReflectionEx.thy
  2766 
  2767 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  2768 command 'statespace' that is similar to 'record', but introduces an
  2769 abstract specification based on the locale infrastructure instead of
  2770 HOL types.  This leads to extra flexibility in composing state spaces,
  2771 in particular multiple inheritance and renaming of components.
  2772 
  2773 
  2774 *** HOL-Complex ***
  2775 
  2776 * Hyperreal: Functions root and sqrt are now defined on negative real
  2777 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  2778 Nonnegativity side conditions have been removed from many lemmas, so
  2779 that more subgoals may now be solved by simplification; potential
  2780 INCOMPATIBILITY.
  2781 
  2782 * Real: new type classes formalize real normed vector spaces and
  2783 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  2784 and norm :: 'a => real.
  2785 
  2786 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  2787 reals into other types. The overloaded constant Reals :: 'a set is now
  2788 defined as range of_real; potential INCOMPATIBILITY.
  2789 
  2790 * Real: proper support for ML code generation, including 'quickcheck'.
  2791 Reals are implemented as arbitrary precision rationals.
  2792 
  2793 * Hyperreal: Several constants that previously worked only for the
  2794 reals have been generalized, so they now work over arbitrary vector
  2795 spaces. Type annotations may need to be added in some cases; potential
  2796 INCOMPATIBILITY.
  2797 
  2798   Infinitesimal  :: ('a::real_normed_vector) star set
  2799   HFinite        :: ('a::real_normed_vector) star set
  2800   HInfinite      :: ('a::real_normed_vector) star set
  2801   approx         :: ('a::real_normed_vector) star => 'a star => bool
  2802   monad          :: ('a::real_normed_vector) star => 'a star set
  2803   galaxy         :: ('a::real_normed_vector) star => 'a star set
  2804   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  2805   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  2806   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  2807   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  2808   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  2809   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  2810   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  2811   sgn            :: 'a::real_normed_vector => 'a
  2812   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  2813 
  2814 * Complex: Some complex-specific constants are now abbreviations for
  2815 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  2816 hnorm.  Other constants have been entirely removed in favor of the
  2817 polymorphic versions (INCOMPATIBILITY):
  2818 
  2819   approx        <-- capprox
  2820   HFinite       <-- CFinite
  2821   HInfinite     <-- CInfinite
  2822   Infinitesimal <-- CInfinitesimal
  2823   monad         <-- cmonad
  2824   galaxy        <-- cgalaxy
  2825   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  2826   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  2827   (ns)deriv     <-- (ns)cderiv
  2828 
  2829 
  2830 *** HOL-Algebra ***
  2831 
  2832 * Formalisation of ideals and the quotient construction over rings.
  2833 
  2834 * Order and lattice theory no longer based on records.
  2835 INCOMPATIBILITY.
  2836 
  2837 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  2838 greatest_closed.  INCOMPATIBILITY.
  2839 
  2840 * Method algebra is now set up via an attribute.  For examples see
  2841 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  2842 of algebraic structures.
  2843 
  2844 * Renamed theory CRing to Ring.
  2845 
  2846 
  2847 *** HOL-Nominal ***
  2848 
  2849 * Substantial, yet incomplete support for nominal datatypes (binding
  2850 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  2851 src/HOL/Nominal/Examples.  Prospective users should consult
  2852 http://isabelle.in.tum.de/nominal/
  2853 
  2854 
  2855 *** ML ***
  2856 
  2857 * ML basics: just one true type int, which coincides with IntInf.int
  2858 (even on SML/NJ).
  2859 
  2860 * ML within Isar: antiquotations allow to embed statically-checked
  2861 formal entities in the source, referring to the context available at
  2862 compile-time.  For example:
  2863 
  2864 ML {* @{sort "{zero,one}"} *}
  2865 ML {* @{typ "'a => 'b"} *}
  2866 ML {* @{term "%x. x"} *}
  2867 ML {* @{prop "x == y"} *}
  2868 ML {* @{ctyp "'a => 'b"} *}
  2869 ML {* @{cterm "%x. x"} *}
  2870 ML {* @{cprop "x == y"} *}
  2871 ML {* @{thm asm_rl} *}
  2872 ML {* @{thms asm_rl} *}
  2873 ML {* @{type_name c} *}
  2874 ML {* @{type_syntax c} *}
  2875 ML {* @{const_name c} *}
  2876 ML {* @{const_syntax c} *}
  2877 ML {* @{context} *}
  2878 ML {* @{theory} *}
  2879 ML {* @{theory Pure} *}
  2880 ML {* @{theory_ref} *}
  2881 ML {* @{theory_ref Pure} *}
  2882 ML {* @{simpset} *}
  2883 ML {* @{claset} *}
  2884 ML {* @{clasimpset} *}
  2885 
  2886 The same works for sources being ``used'' within an Isar context.
  2887 
  2888 * ML in Isar: improved error reporting; extra verbosity with
  2889 ML_Context.trace enabled.
  2890 
  2891 * Pure/General/table.ML: the join operations now works via exceptions
  2892 DUP/SAME instead of type option. This is simpler in simple cases, and
  2893 admits slightly more efficient complex applications.
  2894 
  2895 * Pure: 'advanced' translation functions (parse_translation etc.) now
  2896 use Context.generic instead of just theory.
  2897 
  2898 * Pure: datatype Context.generic joins theory/Proof.context and
  2899 provides some facilities for code that works in either kind of
  2900 context, notably GenericDataFun for uniform theory and proof data.
  2901 
  2902 * Pure: simplified internal attribute type, which is now always
  2903 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  2904 local (Proof.context) attributes have been discontinued, while
  2905 minimizing code duplication. Thm.rule_attribute and
  2906 Thm.declaration_attribute build canonical attributes; see also structure
  2907 Context for further operations on Context.generic, notably
  2908 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  2909 declarations and definitions.
  2910 
  2911 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  2912 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  2913 init only required for impure data. INCOMPATIBILITY: empty really need
  2914 to be empty (no dependencies on theory content!)
  2915 
  2916 * Pure/kernel: consts certification ignores sort constraints given in
  2917 signature declarations. (This information is not relevant to the
  2918 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  2919 potential INCOMPATIBILITY.
  2920 
  2921 * Pure: axiomatic type classes are now purely definitional, with
  2922 explicit proofs of class axioms and super class relations performed
  2923 internally. See Pure/axclass.ML for the main internal interfaces --
  2924 notably AxClass.define_class supercedes AxClass.add_axclass, and
  2925 AxClass.axiomatize_class/classrel/arity supersede
  2926 Sign.add_classes/classrel/arities.
  2927 
  2928 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  2929 global/local versions on theory vs. Proof.context have been
  2930 discontinued; Attrib.syntax and Method.syntax have been adapted
  2931 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  2932 attributes, methods, etc.
  2933 
  2934 * Pure: several functions of signature "... -> theory -> theory * ..."
  2935 have been reoriented to "... -> theory -> ... * theory" in order to
  2936 allow natural usage in combination with the ||>, ||>>, |-> and
  2937 fold_map combinators.
  2938 
  2939 * Pure: official theorem names (closed derivations) and additional
  2940 comments (tags) are now strictly separate.  Name hints -- which are
  2941 maintained as tags -- may be attached any time without affecting the
  2942 derivation.
  2943 
  2944 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  2945 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  2946 achieve the old behaviour.
  2947 
  2948 * Pure: the "Goal" constant is now called "prop", supporting a
  2949 slightly more general idea of ``protecting'' meta-level rule
  2950 statements.
  2951 
  2952 * Pure: Logic.(un)varify only works in a global context, which is now
  2953 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  2954 Logic.legacy_(un)varify as temporary workaround.
  2955 
  2956 * Pure: structure Name provides scalable operations for generating
  2957 internal variable names, notably Name.variants etc.  This replaces
  2958 some popular functions from term.ML:
  2959 
  2960   Term.variant		->  Name.variant
  2961   Term.variantlist	->  Name.variant_list
  2962   Term.invent_names	->  Name.invent_list
  2963 
  2964 Note that low-level renaming rarely occurs in new code -- operations
  2965 from structure Variable are used instead (see below).
  2966 
  2967 * Pure: structure Variable provides fundamental operations for proper
  2968 treatment of fixed/schematic variables in a context.  For example,
  2969 Variable.import introduces fixes for schematics of given facts and
  2970 Variable.export reverses the effect (up to renaming) -- this replaces
  2971 various freeze_thaw operations.
  2972 
  2973 * Pure: structure Goal provides simple interfaces for
  2974 init/conclude/finish and tactical prove operations (replacing former
  2975 Tactic.prove).  Goal.prove is the canonical way to prove results
  2976 within a given context; Goal.prove_global is a degraded version for
  2977 theory level goals, including a global Drule.standard.  Note that
  2978 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  2979 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  2980 in a locale context).
  2981 
  2982 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  2983 and type checking (Syntax.check_term etc.), with common combinations
  2984 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  2985 which are considered legacy and await removal.
  2986 
  2987 * Pure/Syntax: generic interfaces for type unchecking
  2988 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  2989 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  2990 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  2991 available for convenience, but refer to the very same operations using
  2992 a mere theory instead of a full context.
  2993 
  2994 * Isar: simplified treatment of user-level errors, using exception
  2995 ERROR of string uniformly.  Function error now merely raises ERROR,
  2996 without any side effect on output channels.  The Isar toplevel takes
  2997 care of proper display of ERROR exceptions.  ML code may use plain
  2998 handle/can/try; cat_error may be used to concatenate errors like this:
  2999 
  3000   ... handle ERROR msg => cat_error msg "..."
  3001 
  3002 Toplevel ML code (run directly or through the Isar toplevel) may be
  3003 embedded into the Isar toplevel with exception display/debug like
  3004 this:
  3005 
  3006   Isar.toplevel (fn () => ...)
  3007 
  3008 INCOMPATIBILITY, removed special transform_error facilities, removed
  3009 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  3010 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  3011 -- use plain ERROR instead.
  3012 
  3013 * Isar: theory setup now has type (theory -> theory), instead of a
  3014 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  3015 
  3016 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  3017 ProofContext.debug/verbose flags.
  3018 
  3019 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  3020 theory before entering a proof state.  Transactions now always see a
  3021 quasi-functional intermediate checkpoint, both in interactive and
  3022 batch mode.
  3023 
  3024 * Isar: simplified interfaces for outer syntax.  Renamed
  3025 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  3026 OuterSyntax.add_parsers -- this functionality is now included in
  3027 OuterSyntax.command etc.  INCOMPATIBILITY.
  3028 
  3029 * Simplifier: the simpset of a running simplification process now
  3030 contains a proof context (cf. Simplifier.the_context), which is the
  3031 very context that the initial simpset has been retrieved from (by
  3032 simpset_of/local_simpset_of).  Consequently, all plug-in components
  3033 (solver, looper etc.) may depend on arbitrary proof data.
  3034 
  3035 * Simplifier.inherit_context inherits the proof context (plus the
  3036 local bounds) of the current simplification process; any simproc
  3037 etc. that calls the Simplifier recursively should do this!  Removed
  3038 former Simplifier.inherit_bounds, which is already included here --
  3039 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  3040 specify an explicit context using Simplifier.context/theory_context.
  3041 
  3042 * Simplifier/Classical Reasoner: more abstract interfaces
  3043 change_simpset/claset for modifying the simpset/claset reference of a
  3044 theory; raw versions simpset/claset_ref etc. have been discontinued --
  3045 INCOMPATIBILITY.
  3046 
  3047 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  3048 "Trueprop" etc.
  3049 
  3050 
  3051 *** System ***
  3052 
  3053 * settings: the default heap location within ISABELLE_HOME_USER now
  3054 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  3055 Isabelle installations.
  3056 
  3057 * isabelle-process: option -S (secure mode) disables some critical
  3058 operations, notably runtime compilation and evaluation of ML source
  3059 code.
  3060 
  3061 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  3062 
  3063 * Support for parallel execution, using native multicore support of
  3064 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  3065 independent theories, according to the given theory header
  3066 specifications. The maximum number of worker threads is specified via
  3067 usedir option -M or the "max-threads" setting in Proof General. A
  3068 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  3069 to 6 on a 8-core machine.  User-code needs to observe certain
  3070 guidelines for thread-safe programming, see appendix A in the Isar
  3071 Implementation manual.
  3072 
  3073 
  3074 
  3075 New in Isabelle2005 (October 2005)
  3076 ----------------------------------
  3077 
  3078 *** General ***
  3079 
  3080 * Theory headers: the new header syntax for Isar theories is
  3081 
  3082   theory <name>
  3083   imports <theory1> ... <theoryN>
  3084   uses <file1> ... <fileM>
  3085   begin
  3086 
  3087 where the 'uses' part is optional.  The previous syntax
  3088 
  3089   theory <name> = <theory1> + ... + <theoryN>:
  3090 
  3091 will disappear in the next release.  Use isatool fixheaders to convert
  3092 existing theory files.  Note that there is no change in ancient
  3093 non-Isar theories now, but these will disappear soon.
  3094 
  3095 * Theory loader: parent theories can now also be referred to via
  3096 relative and absolute paths.
  3097 
  3098 * Command 'find_theorems' searches for a list of criteria instead of a
  3099 list of constants. Known criteria are: intro, elim, dest, name:string,
  3100 simp:term, and any term. Criteria can be preceded by '-' to select
  3101 theorems that do not match. Intro, elim, dest select theorems that
  3102 match the current goal, name:s selects theorems whose fully qualified
  3103 name contain s, and simp:term selects all simplification rules whose
  3104 lhs match term.  Any other term is interpreted as pattern and selects
  3105 all theorems matching the pattern. Available in ProofGeneral under
  3106 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  3107 
  3108   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  3109 
  3110 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  3111 matching the current goal as introduction rule and not having "HOL."
  3112 in their name (i.e. not being defined in theory HOL).
  3113 
  3114 * Command 'thms_containing' has been discontinued in favour of
  3115 'find_theorems'; INCOMPATIBILITY.
  3116 
  3117 * Communication with Proof General is now 8bit clean, which means that
  3118 Unicode text in UTF-8 encoding may be used within theory texts (both
  3119 formal and informal parts).  Cf. option -U of the Isabelle Proof
  3120 General interface.  Here are some simple examples (cf. src/HOL/ex):
  3121 
  3122   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  3123   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  3124 
  3125 * Improved efficiency of the Simplifier and, to a lesser degree, the
  3126 Classical Reasoner.  Typical big applications run around 2 times
  3127 faster.
  3128 
  3129 
  3130 *** Document preparation ***
  3131 
  3132 * Commands 'display_drafts' and 'print_drafts' perform simple output
  3133 of raw sources.  Only those symbols that do not require additional
  3134 LaTeX packages (depending on comments in isabellesym.sty) are
  3135 displayed properly, everything else is left verbatim.  isatool display
  3136 and isatool print are used as front ends (these are subject to the
  3137 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  3138 
  3139 * Command tags control specific markup of certain regions of text,
  3140 notably folding and hiding.  Predefined tags include "theory" (for
  3141 theory begin and end), "proof" for proof commands, and "ML" for
  3142 commands involving ML code; the additional tags "visible" and
  3143 "invisible" are unused by default.  Users may give explicit tag
  3144 specifications in the text, e.g. ''by %invisible (auto)''.  The
  3145 interpretation of tags is determined by the LaTeX job during document
  3146 preparation: see option -V of isatool usedir, or options -n and -t of
  3147 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  3148 \isadroptag.
  3149 
  3150 Several document versions may be produced at the same time via isatool
  3151 usedir (the generated index.html will link all of them).  Typical
  3152 specifications include ''-V document=theory,proof,ML'' to present
  3153 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  3154 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  3155 these parts without any formal replacement text.  The Isabelle site
  3156 default settings produce ''document'' and ''outline'' versions as
  3157 specified above.
  3158 
  3159 * Several new antiquotations:
  3160 
  3161   @{term_type term} prints a term with its type annotated;
  3162 
  3163   @{typeof term} prints the type of a term;
  3164 
  3165   @{const const} is the same as @{term const}, but checks that the
  3166   argument is a known logical constant;
  3167 
  3168   @{term_style style term} and @{thm_style style thm} print a term or
  3169   theorem applying a "style" to it
  3170 
  3171   @{ML text}
  3172 
  3173 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  3174 definitions, equations, inequations etc., 'concl' printing only the
  3175 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  3176 to print the specified premise.  TermStyle.add_style provides an ML
  3177 interface for introducing further styles.  See also the "LaTeX Sugar"
  3178 document practical applications.  The ML antiquotation prints
  3179 type-checked ML expressions verbatim.
  3180 
  3181 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  3182 and 'text' support optional locale specification '(in loc)', which
  3183 specifies the default context for interpreting antiquotations.  For
  3184 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  3185 
  3186 * Option 'locale=NAME' of antiquotations specifies an alternative
  3187 context interpreting the subsequent argument.  For example: @{thm
  3188 [locale=lattice] inf_assoc}.
  3189 
  3190 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  3191 a proof context.
  3192 
  3193 * Proper output of antiquotations for theory commands involving a
  3194 proof context (such as 'locale' or 'theorem (in loc) ...').
  3195 
  3196 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  3197 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  3198 
  3199 * isatool usedir: new option -C (default true) controls whether option
  3200 -D should include a copy of the original document directory; -C false
  3201 prevents unwanted effects such as copying of administrative CVS data.
  3202 
  3203 
  3204 *** Pure ***
  3205 
  3206 * Considerably improved version of 'constdefs' command.  Now performs
  3207 automatic type-inference of declared constants; additional support for
  3208 local structure declarations (cf. locales and HOL records), see also
  3209 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  3210 sequential dependencies of definitions within a single 'constdefs'
  3211 section; moreover, the declared name needs to be an identifier.  If
  3212 all fails, consider to fall back on 'consts' and 'defs' separately.
  3213 
  3214 * Improved indexed syntax and implicit structures.  First of all,
  3215 indexed syntax provides a notational device for subscripted
  3216 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  3217 expressions.  Secondly, in a local context with structure
  3218 declarations, number indexes \<^sub>n or the empty index (default
  3219 number 1) refer to a certain fixed variable implicitly; option
  3220 show_structs controls printing of implicit structures.  Typical
  3221 applications of these concepts involve record types and locales.
  3222 
  3223 * New command 'no_syntax' removes grammar declarations (and
  3224 translations) resulting from the given syntax specification, which is
  3225 interpreted in the same manner as for the 'syntax' command.
  3226 
  3227 * 'Advanced' translation functions (parse_translation etc.) may depend
  3228 on the signature of the theory context being presently used for
  3229 parsing/printing, see also isar-ref manual.
  3230 
  3231 * Improved 'oracle' command provides a type-safe interface to turn an
  3232 ML expression of type theory -> T -> term into a primitive rule of
  3233 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  3234 is already included here); see also FOL/ex/IffExample.thy;
  3235 INCOMPATIBILITY.
  3236 
  3237 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  3238 before); "cI" is no longer bound, use "c.intro" instead.
  3239 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  3240 axclasses vs. locales.
  3241 
  3242 * Improved internal renaming of symbolic identifiers -- attach primes
  3243 instead of base 26 numbers.
  3244 
  3245 * New flag show_question_marks controls printing of leading question
  3246 marks in schematic variable names.
  3247 
  3248 * In schematic variable names, *any* symbol following \<^isub> or
  3249 \<^isup> is now treated as part of the base name.  For example, the
  3250 following works without printing of awkward ".0" indexes:
  3251 
  3252   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  3253     by simp
  3254 
  3255 * Inner syntax includes (*(*nested*) comments*).
  3256 
  3257 * Pretty printer now supports unbreakable blocks, specified in mixfix
  3258 annotations as "(00...)".
  3259 
  3260 * Clear separation of logical types and nonterminals, where the latter
  3261 may only occur in 'syntax' specifications or type abbreviations.
  3262 Before that distinction was only partially implemented via type class
  3263 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  3264 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  3265 exotic syntax specifications may require further adaption
  3266 (e.g. Cube/Cube.thy).
  3267 
  3268 * Removed obsolete type class "logic", use the top sort {} instead.
  3269 Note that non-logical types should be declared as 'nonterminals'
  3270 rather than 'types'.  INCOMPATIBILITY for new object-logic
  3271 specifications.
  3272 
  3273 * Attributes 'induct' and 'cases': type or set names may now be
  3274 locally fixed variables as well.
  3275 
  3276 * Simplifier: can now control the depth to which conditional rewriting
  3277 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  3278 Limit.
  3279 
  3280 * Simplifier: simplification procedures may now take the current
  3281 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  3282 interface), which is very useful for calling the Simplifier
  3283 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  3284 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  3285 low-level mk_simproc no longer applies Logic.varify internally, to
  3286 allow for use in a context of fixed variables.
  3287 
  3288 * thin_tac now works even if the assumption being deleted contains !!
  3289 or ==>.  More generally, erule now works even if the major premise of
  3290 the elimination rule contains !! or ==>.
  3291 
  3292 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  3293 
  3294 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  3295 from Pure, which contains all common declarations already.  Both
  3296 theories are defined via plain Isabelle/Isar .thy files.
  3297 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  3298 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  3299 use isatool fixcpure to adapt your theory and ML sources.
  3300 
  3301 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  3302 selections of theorems in named facts via index ranges.
  3303 
  3304 * 'print_theorems': in theory mode, really print the difference
  3305 wrt. the last state (works for interactive theory development only),
  3306 in proof mode print all local facts (cf. 'print_facts');
  3307 
  3308 * 'hide': option '(open)' hides only base names.
  3309 
  3310 * More efficient treatment of intermediate checkpoints in interactive
  3311 theory development.
  3312 
  3313 * Code generator is now invoked via code_module (incremental code
  3314 generation) and code_library (modular code generation, ML structures
  3315 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  3316 must be quoted when used as identifiers.
  3317 
  3318 * New 'value' command for reading, evaluating and printing terms using
  3319 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  3320 quoted when used as identifier.
  3321 
  3322 
  3323 *** Locales ***
  3324 
  3325 * New commands for the interpretation of locale expressions in
  3326 theories (1), locales (2) and proof contexts (3).  These generate
  3327 proof obligations from the expression specification.  After the
  3328 obligations have been discharged, theorems of the expression are added
  3329 to the theory, target locale or proof context.  The synopsis of the
  3330 commands is a follows:
  3331 
  3332   (1) interpretation expr inst
  3333   (2) interpretation target < expr
  3334   (3) interpret expr inst
  3335 
  3336 Interpretation in theories and proof contexts require a parameter
  3337 instantiation of terms from the current context.  This is applied to
  3338 specifications and theorems of the interpreted expression.
  3339 Interpretation in locales only permits parameter renaming through the
  3340 locale expression.  Interpretation is smart in that interpretations
  3341 that are active already do not occur in proof obligations, neither are
  3342 instantiated theorems stored in duplicate.  Use 'print_interps' to
  3343 inspect active interpretations of a particular locale.  For details,
  3344 see the Isar Reference manual.  Examples can be found in
  3345 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  3346 
  3347 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  3348 'interpret' instead.
  3349 
  3350 * New context element 'constrains' for adding type constraints to
  3351 parameters.
  3352 
  3353 * Context expressions: renaming of parameters with syntax
  3354 redeclaration.
  3355 
  3356 * Locale declaration: 'includes' disallowed.
  3357 
  3358 * Proper static binding of attribute syntax -- i.e. types / terms /
  3359 facts mentioned as arguments are always those of the locale definition
  3360 context, independently of the context of later invocations.  Moreover,
  3361 locale operations (renaming and type / term instantiation) are applied
  3362 to attribute arguments as expected.
  3363 
  3364 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  3365 actual attributes; rare situations may require Attrib.attribute to
  3366 embed those attributes into Attrib.src that lack concrete syntax.
  3367 Attribute implementations need to cooperate properly with the static
  3368 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  3369 Attrib.XXX_thm etc. already do the right thing without further
  3370 intervention.  Only unusual applications -- such as "where" or "of"
  3371 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  3372 on the context and the facts involved -- may have to assign parsed
  3373 values to argument tokens explicitly.
  3374 
  3375 * Changed parameter management in theorem generation for long goal
  3376 statements with 'includes'.  INCOMPATIBILITY: produces a different
  3377 theorem statement in rare situations.
  3378 
  3379 * Locale inspection command 'print_locale' omits notes elements.  Use
  3380 'print_locale!' to have them included in the output.
  3381 
  3382 
  3383 *** Provers ***
  3384 
  3385 * Provers/hypsubst.ML: improved version of the subst method, for
  3386 single-step rewriting: it now works in bound variable contexts. New is
  3387 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  3388 rewrite a different subterm than the original subst method, which is
  3389 still available as 'simplesubst'.
  3390 
  3391 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  3392 and quasi orders.
  3393 
  3394 * Provers/trancl.ML: new transitivity reasoner for transitive and
  3395 reflexive-transitive closure of relations.
  3396 
  3397 * Provers/blast.ML: new reference depth_limit to make blast's depth
  3398 limit (previously hard-coded with a value of 20) user-definable.
  3399 
  3400 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  3401 is peformed already.  Object-logics merely need to finish their
  3402 initial simpset configuration as before.  INCOMPATIBILITY.
  3403 
  3404 
  3405 *** HOL ***
  3406 
  3407 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  3408 
  3409   syntax (epsilon)
  3410     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  3411 
  3412 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  3413 and x-symbol; use option '-m epsilon' to get it actually printed.
  3414 Moreover, the mathematically important symbolic identifier \<epsilon>
  3415 becomes available as variable, constant etc.  INCOMPATIBILITY,
  3416 
  3417 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  3418 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  3419 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  3420 support corresponding Isar calculations.
  3421 
  3422 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  3423 instead of ":".
  3424 
  3425 * theory SetInterval: changed the syntax for open intervals:
  3426 
  3427   Old       New
  3428   {..n(}    {..<n}
  3429   {)n..}    {n<..}
  3430   {m..n(}   {m..<n}
  3431   {)m..n}   {m<..n}
  3432   {)m..n(}  {m<..<n}
  3433 
  3434 The old syntax is still supported but will disappear in the next
  3435 release.  For conversion use the following Emacs search and replace
  3436 patterns (these are not perfect but work quite well):
  3437 
  3438   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  3439   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  3440 
  3441 * Theory Commutative_Ring (in Library): method comm_ring for proving
  3442 equalities in commutative rings; method 'algebra' provides a generic
  3443 interface.
  3444 
  3445 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  3446 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  3447 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  3448 be a tuple pattern.
  3449 
  3450 Some new syntax forms are available:
  3451 
  3452   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  3453   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  3454   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  3455   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  3456 
  3457 The latter form "\<Sum>x < k. e" used to be based on a separate
  3458 function "Summation", which has been discontinued.
  3459 
  3460 * theory Finite_Set: in structured induction proofs, the insert case
  3461 is now 'case (insert x F)' instead of the old counterintuitive 'case
  3462 (insert F x)'.
  3463 
  3464 * The 'refute' command has been extended to support a much larger
  3465 fragment of HOL, including axiomatic type classes, constdefs and
  3466 typedefs, inductive datatypes and recursion.
  3467 
  3468 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  3469 Requires zChaff with proof generation to be installed.  See
  3470 HOL/ex/SAT_Examples.thy for examples.
  3471 
  3472 * Datatype induction via method 'induct' now preserves the name of the
  3473 induction variable. For example, when proving P(xs::'a list) by
  3474 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  3475 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  3476 in unstructured proof scripts.
  3477 
  3478 * Reworked implementation of records.  Improved scalability for
  3479 records with many fields, avoiding performance problems for type
  3480 inference. Records are no longer composed of nested field types, but
  3481 of nested extension types. Therefore the record type only grows linear
  3482 in the number of extensions and not in the number of fields.  The
  3483 top-level (users) view on records is preserved.  Potential
  3484 INCOMPATIBILITY only in strange cases, where the theory depends on the
  3485 old record representation. The type generated for a record is called
  3486 <record_name>_ext_type.
  3487 
  3488 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  3489 proofs triggered by a record definition or a simproc (if
  3490 quick_and_dirty is enabled).  Definitions of large records can take
  3491 quite long.
  3492 
  3493 New simproc record_upd_simproc for simplification of multiple record
  3494 updates enabled by default.  Moreover, trivial updates are also
  3495 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  3496 occasionally, since simplification is more powerful by default.
  3497 
  3498 * typedef: proper support for polymorphic sets, which contain extra
  3499 type-variables in the term.
  3500 
  3501 * Simplifier: automatically reasons about transitivity chains
  3502 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  3503 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  3504 old proofs break occasionally as simplification may now solve more
  3505 goals than previously.
  3506 
  3507 * Simplifier: converts x <= y into x = y if assumption y <= x is
  3508 present.  Works for all partial orders (class "order"), in particular
  3509 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  3510 just like y <= x.
  3511 
  3512 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  3513 bound variable or a constant then the let is unfolded.  Otherwise
  3514 first a is simplified to b, and then f b is simplified to g. If
  3515 possible we abstract b from g arriving at "let x = b in h x",
  3516 otherwise we unfold the let and arrive at g.  The simproc can be
  3517 enabled/disabled by the reference use_let_simproc.  Potential
  3518 INCOMPATIBILITY since simplification is more powerful by default.
  3519 
  3520 * Classical reasoning: the meson method now accepts theorems as arguments.
  3521 
  3522 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  3523 jobs to provide advice on the provability of subgoals.
  3524 
  3525 * Theory OrderedGroup and Ring_and_Field: various additions and
  3526 improvements to faciliate calculations involving equalities and
  3527 inequalities.
  3528 
  3529 The following theorems have been eliminated or modified
  3530 (INCOMPATIBILITY):
  3531 
  3532   abs_eq             now named abs_of_nonneg
  3533   abs_of_ge_0        now named abs_of_nonneg
  3534   abs_minus_eq       now named abs_of_nonpos
  3535   imp_abs_id         now named abs_of_nonneg
  3536   imp_abs_neg_id     now named abs_of_nonpos
  3537   mult_pos           now named mult_pos_pos
  3538   mult_pos_le        now named mult_nonneg_nonneg
  3539   mult_pos_neg_le    now named mult_nonneg_nonpos
  3540   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  3541   mult_neg           now named mult_neg_neg
  3542   mult_neg_le        now named mult_nonpos_nonpos
  3543 
  3544 * The following lemmas in Ring_and_Field have been added to the simplifier:
  3545      
  3546      zero_le_square
  3547      not_square_less_zero 
  3548 
  3549   The following lemmas have been deleted from Real/RealPow:
  3550   
  3551      realpow_zero_zero
  3552      realpow_two
  3553      realpow_less
  3554      zero_le_power
  3555      realpow_two_le
  3556      abs_realpow_two
  3557      realpow_two_abs     
  3558 
  3559 * Theory Parity: added rules for simplifying exponents.
  3560 
  3561 * Theory List:
  3562 
  3563 The following theorems have been eliminated or modified
  3564 (INCOMPATIBILITY):
  3565 
  3566   list_all_Nil       now named list_all.simps(1)
  3567   list_all_Cons      now named list_all.simps(2)
  3568   list_all_conv      now named list_all_iff
  3569   set_mem_eq         now named mem_iff
  3570 
  3571 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  3572 asymptotic "big O" calculations.  See the notes in BigO.thy.
  3573 
  3574 
  3575 *** HOL-Complex ***
  3576 
  3577 * Theory RealDef: better support for embedding natural numbers and
  3578 integers in the reals.
  3579 
  3580 The following theorems have been eliminated or modified
  3581 (INCOMPATIBILITY):
  3582 
  3583   exp_ge_add_one_self  now requires no hypotheses
  3584   real_of_int_add      reversed direction of equality (use [symmetric])
  3585   real_of_int_minus    reversed direction of equality (use [symmetric])
  3586   real_of_int_diff     reversed direction of equality (use [symmetric])
  3587   real_of_int_mult     reversed direction of equality (use [symmetric])
  3588 
  3589 * Theory RComplete: expanded support for floor and ceiling functions.
  3590 
  3591 * Theory Ln is new, with properties of the natural logarithm
  3592 
  3593 * Hyperreal: There is a new type constructor "star" for making
  3594 nonstandard types.  The old type names are now type synonyms:
  3595 
  3596   hypreal = real star
  3597   hypnat = nat star
  3598   hcomplex = complex star
  3599 
  3600 * Hyperreal: Many groups of similarly-defined constants have been
  3601 replaced by polymorphic versions (INCOMPATIBILITY):
  3602 
  3603   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  3604 
  3605   starset      <-- starsetNat, starsetC
  3606   *s*          <-- *sNat*, *sc*
  3607   starset_n    <-- starsetNat_n, starsetC_n
  3608   *sn*         <-- *sNatn*, *scn*
  3609   InternalSets <-- InternalNatSets, InternalCSets
  3610 
  3611   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  3612   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  3613   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  3614   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  3615   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  3616 
  3617 * Hyperreal: Many type-specific theorems have been removed in favor of
  3618 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  3619 
  3620   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  3621   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  3622   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  3623   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  3624   right_minus <-- hypreal_add_minus
  3625   left_minus <-- {hypreal,hcomplex}_add_minus_left
  3626   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  3627   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  3628   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  3629   mult_1_right <-- hcomplex_mult_one_right
  3630   mult_zero_left <-- hcomplex_mult_zero_left
  3631   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  3632   right_distrib <-- hypnat_add_mult_distrib2
  3633   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  3634   right_inverse <-- hypreal_mult_inverse
  3635   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  3636   order_refl <-- {hypreal,hypnat}_le_refl
  3637   order_trans <-- {hypreal,hypnat}_le_trans
  3638   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  3639   order_less_le <-- {hypreal,hypnat}_less_le
  3640   linorder_linear <-- {hypreal,hypnat}_le_linear
  3641   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  3642   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  3643   add_nonneg_nonneg <-- hypreal_le_add_order
  3644 
  3645 * Hyperreal: Separate theorems having to do with type-specific
  3646 versions of constants have been merged into theorems that apply to the
  3647 new polymorphic constants (INCOMPATIBILITY):
  3648 
  3649   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  3650   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  3651   STAR_Un <-- {STAR,NatStar,STARC}_Un
  3652   STAR_Int <-- {STAR,NatStar,STARC}_Int
  3653   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  3654   STAR_subset <-- {STAR,NatStar,STARC}_subset
  3655   STAR_mem <-- {STAR,NatStar,STARC}_mem
  3656   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  3657   STAR_diff <-- {STAR,STARC}_diff
  3658   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  3659     STARC_hcomplex_of_complex}_image_subset
  3660   starset_n_Un <-- starset{Nat,C}_n_Un
  3661   starset_n_Int <-- starset{Nat,C}_n_Int
  3662   starset_n_Compl <-- starset{Nat,C}_n_Compl
  3663   starset_n_diff <-- starset{Nat,C}_n_diff
  3664   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  3665   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  3666   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  3667   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  3668   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  3669   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  3670   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  3671   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  3672   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  3673   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  3674   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  3675   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  3676   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  3677   starfun_diff <-- starfun{C,RC,CR}_diff
  3678   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  3679   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  3680   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  3681   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  3682   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  3683   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  3684   starfun_Id <-- starfunC_Id
  3685   starfun_approx <-- starfun{Nat,CR}_approx
  3686   starfun_capprox <-- starfun{C,RC}_capprox
  3687   starfun_abs <-- starfunNat_rabs
  3688   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  3689   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  3690   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  3691   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  3692   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  3693   starfun_add_approx <-- starfunCR_add_approx
  3694   starfun_inverse_inverse <-- starfunC_inverse_inverse
  3695   starfun_divide <-- starfun{C,CR,RC}_divide
  3696   starfun_n <-- starfun{Nat,C}_n
  3697   starfun_n_mult <-- starfun{Nat,C}_n_mult
  3698   starfun_n_add <-- starfun{Nat,C}_n_add
  3699   starfun_n_add_minus <-- starfunNat_n_add_minus
  3700   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  3701   starfun_n_minus <-- starfun{Nat,C}_n_minus
  3702   starfun_n_eq <-- starfun{Nat,C}_n_eq
  3703 
  3704   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  3705   star_n_minus <-- {hypreal,hcomplex}_minus
  3706   star_n_diff <-- {hypreal,hcomplex}_diff
  3707   star_n_mult <-- {hypreal,hcomplex}_mult
  3708   star_n_inverse <-- {hypreal,hcomplex}_inverse
  3709   star_n_le <-- {hypreal,hypnat}_le
  3710   star_n_less <-- {hypreal,hypnat}_less
  3711   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  3712   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  3713   star_n_abs <-- hypreal_hrabs
  3714   star_n_divide <-- hcomplex_divide
  3715 
  3716   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  3717   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  3718   star_of_diff <-- hypreal_of_real_diff
  3719   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  3720   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  3721   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  3722   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  3723   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  3724   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  3725   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  3726   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  3727   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  3728   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  3729   star_of_number_of <-- {hypreal,hcomplex}_number_of
  3730   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  3731   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  3732   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  3733   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  3734   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  3735   star_of_power <-- hypreal_of_real_power
  3736   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  3737 
  3738 * Hyperreal: new method "transfer" that implements the transfer
  3739 principle of nonstandard analysis. With a subgoal that mentions
  3740 nonstandard types like "'a star", the command "apply transfer"
  3741 replaces it with an equivalent one that mentions only standard types.
  3742 To be successful, all free variables must have standard types; non-
  3743 standard variables must have explicit universal quantifiers.
  3744 
  3745 * Hyperreal: A theory of Taylor series.
  3746 
  3747 
  3748 *** HOLCF ***
  3749 
  3750 * Discontinued special version of 'constdefs' (which used to support
  3751 continuous functions) in favor of the general Pure one with full
  3752 type-inference.
  3753 
  3754 * New simplification procedure for solving continuity conditions; it
  3755 is much faster on terms with many nested lambda abstractions (cubic
  3756 instead of exponential time).
  3757 
  3758 * New syntax for domain package: selector names are now optional.
  3759 Parentheses should be omitted unless argument is lazy, for example:
  3760 
  3761   domain 'a stream = cons "'a" (lazy "'a stream")
  3762 
  3763 * New command 'fixrec' for defining recursive functions with pattern
  3764 matching; defining multiple functions with mutual recursion is also
  3765 supported.  Patterns may include the constants cpair, spair, up, sinl,
  3766 sinr, or any data constructor defined by the domain package. The given
  3767 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  3768 syntax and examples.
  3769 
  3770 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  3771 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  3772 but the proof obligation additionally includes an admissibility
  3773 requirement. The packages generate instances of class cpo or pcpo,
  3774 with continuity and strictness theorems for Rep and Abs.
  3775 
  3776 * HOLCF: Many theorems have been renamed according to a more standard naming
  3777 scheme (INCOMPATIBILITY):
  3778 
  3779   foo_inject:  "foo$x = foo$y ==> x = y"
  3780   foo_eq:      "(foo$x = foo$y) = (x = y)"
  3781   foo_less:    "(foo$x << foo$y) = (x << y)"
  3782   foo_strict:  "foo$UU = UU"
  3783   foo_defined: "... ==> foo$x ~= UU"
  3784   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  3785 
  3786 
  3787 *** ZF ***
  3788 
  3789 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  3790 including the First Isomorphism Theorem (on quotienting by the kernel
  3791 of a homomorphism).
  3792 
  3793 * ZF/Simplifier: install second copy of type solver that actually
  3794 makes use of TC rules declared to Isar proof contexts (or locales);
  3795 the old version is still required for ML proof scripts.
  3796 
  3797 
  3798 *** Cube ***
  3799 
  3800 * Converted to Isar theory format; use locales instead of axiomatic
  3801 theories.
  3802 
  3803 
  3804 *** ML ***
  3805 
  3806 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  3807 for ||>, ||>>, |>>,
  3808 
  3809 * Pure/library.ML no longer defines its own option datatype, but uses
  3810 that of the SML basis, which has constructors NONE and SOME instead of
  3811 None and Some, as well as exception Option.Option instead of OPTION.
  3812 The functions the, if_none, is_some, is_none have been adapted
  3813 accordingly, while Option.map replaces apsome.
  3814 
  3815 * Pure/library.ML: the exception LIST has been given up in favour of
  3816 the standard exceptions Empty and Subscript, as well as
  3817 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  3818 superceded by the standard hd and tl functions etc.
  3819 
  3820 A number of basic list functions are no longer exported to the ML
  3821 toplevel, as they are variants of predefined functions.  The following
  3822 suggests how one can translate existing code:
  3823 
  3824     rev_append xs ys = List.revAppend (xs, ys)
  3825     nth_elem (i, xs) = List.nth (xs, i)
  3826     last_elem xs = List.last xs
  3827     flat xss = List.concat xss
  3828     seq fs = List.app fs
  3829     partition P xs = List.partition P xs
  3830     mapfilter f xs = List.mapPartial f xs
  3831 
  3832 * Pure/library.ML: several combinators for linear functional
  3833 transformations, notably reverse application and composition:
  3834 
  3835   x |> f                f #> g
  3836   (x, y) |-> f          f #-> g
  3837 
  3838 * Pure/library.ML: introduced/changed precedence of infix operators:
  3839 
  3840   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  3841   infix 2 ?;
  3842   infix 3 o oo ooo oooo;
  3843   infix 4 ~~ upto downto;
  3844 
  3845 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  3846 infix operators.
  3847 
  3848 * Pure/library.ML: natural list combinators fold, fold_rev, and
  3849 fold_map support linear functional transformations and nesting.  For
  3850 example:
  3851 
  3852   fold f [x1, ..., xN] y =
  3853     y |> f x1 |> ... |> f xN
  3854 
  3855   (fold o fold) f [xs1, ..., xsN] y =
  3856     y |> fold f xs1 |> ... |> fold f xsN
  3857 
  3858   fold f [x1, ..., xN] =
  3859     f x1 #> ... #> f xN
  3860 
  3861   (fold o fold) f [xs1, ..., xsN] =
  3862     fold f xs1 #> ... #> fold f xsN
  3863 
  3864 * Pure/library.ML: the following selectors on type 'a option are
  3865 available:
  3866 
  3867   the:               'a option -> 'a  (*partial*)
  3868   these:             'a option -> 'a  where 'a = 'b list
  3869   the_default: 'a -> 'a option -> 'a
  3870   the_list:          'a option -> 'a list
  3871 
  3872 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3873 basic operations for association lists, following natural argument
  3874 order; moreover the explicit equality predicate passed here avoids
  3875 potentially expensive polymorphic runtime equality checks.
  3876 The old functions may be expressed as follows:
  3877 
  3878   assoc = uncurry (AList.lookup (op =))
  3879   assocs = these oo AList.lookup (op =)
  3880   overwrite = uncurry (AList.update (op =)) o swap
  3881 
  3882 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  3883 
  3884   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  3885   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  3886 
  3887 replacing make_keylist and keyfilter (occassionally used)
  3888 Naive rewrites:
  3889 
  3890   make_keylist = AList.make
  3891   keyfilter = AList.find (op =)
  3892 
  3893 * eq_fst and eq_snd now take explicit equality parameter, thus
  3894   avoiding eqtypes. Naive rewrites:
  3895 
  3896     eq_fst = eq_fst (op =)
  3897     eq_snd = eq_snd (op =)
  3898 
  3899 * Removed deprecated apl and apr (rarely used).
  3900   Naive rewrites:
  3901 
  3902     apl (n, op) =>>= curry op n
  3903     apr (op, m) =>>= fn n => op (n, m)
  3904 
  3905 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  3906 provides a reasonably efficient light-weight implementation of sets as
  3907 lists.
  3908 
  3909 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  3910 few new operations; existing lookup and update are now curried to
  3911 follow natural argument order (for use with fold etc.);
  3912 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  3913 
  3914 * Pure/General: output via the Isabelle channels of
  3915 writeln/warning/error etc. is now passed through Output.output, with a
  3916 hook for arbitrary transformations depending on the print_mode
  3917 (cf. Output.add_mode -- the first active mode that provides a output
  3918 function wins).  Already formatted output may be embedded into further
  3919 text via Output.raw; the result of Pretty.string_of/str_of and derived
  3920 functions (string_of_term/cterm/thm etc.) is already marked raw to
  3921 accommodate easy composition of diagnostic messages etc.  Programmers
  3922 rarely need to care about Output.output or Output.raw at all, with
  3923 some notable exceptions: Output.output is required when bypassing the
  3924 standard channels (writeln etc.), or in token translations to produce
  3925 properly formatted results; Output.raw is required when capturing
  3926 already output material that will eventually be presented to the user
  3927 a second time.  For the default print mode, both Output.output and
  3928 Output.raw have no effect.
  3929 
  3930 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  3931 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  3932 cumulative results are displayed at the end of a batch session.
  3933 
  3934 * Pure/General: File.sysify_path and File.quote_sysify path have been
  3935 replaced by File.platform_path and File.shell_path (with appropriate
  3936 hooks).  This provides a clean interface for unusual systems where the
  3937 internal and external process view of file names are different.
  3938 
  3939 * Pure: more efficient orders for basic syntactic entities: added
  3940 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  3941 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  3942 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  3943 orders now -- potential INCOMPATIBILITY for code that depends on a
  3944 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  3945 Library.sort_strings on result).
  3946 
  3947 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  3948 fold_types traverse types/terms from left to right, observing natural
  3949 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  3950 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  3951 
  3952 * Pure: name spaces have been refined, with significant changes of the
  3953 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  3954 to extern(_table).  The plain name entry path is superceded by a
  3955 general 'naming' context, which also includes the 'policy' to produce
  3956 a fully qualified name and external accesses of a fully qualified
  3957 name; NameSpace.extend is superceded by context dependent
  3958 Sign.declare_name.  Several theory and proof context operations modify
  3959 the naming context.  Especially note Theory.restore_naming and
  3960 ProofContext.restore_naming to get back to a sane state; note that
  3961 Theory.add_path is no longer sufficient to recover from
  3962 Theory.absolute_path in particular.
  3963 
  3964 * Pure: new flags short_names (default false) and unique_names
  3965 (default true) for controlling output of qualified names.  If
  3966 short_names is set, names are printed unqualified.  If unique_names is
  3967 reset, the name prefix is reduced to the minimum required to achieve
  3968 the original result when interning again, even if there is an overlap
  3969 with earlier declarations.
  3970 
  3971 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  3972 now 'extend', and 'merge' gets an additional Pretty.pp argument
  3973 (useful for printing error messages).  INCOMPATIBILITY.
  3974 
  3975 * Pure: major reorganization of the theory context.  Type Sign.sg and
  3976 Theory.theory are now identified, referring to the universal
  3977 Context.theory (see Pure/context.ML).  Actual signature and theory
  3978 content is managed as theory data.  The old code and interfaces were
  3979 spread over many files and structures; the new arrangement introduces
  3980 considerable INCOMPATIBILITY to gain more clarity:
  3981 
  3982   Context -- theory management operations (name, identity, inclusion,
  3983     parents, ancestors, merge, etc.), plus generic theory data;
  3984 
  3985   Sign -- logical signature and syntax operations (declaring consts,
  3986     types, etc.), plus certify/read for common entities;
  3987 
  3988   Theory -- logical theory operations (stating axioms, definitions,
  3989     oracles), plus a copy of logical signature operations (consts,
  3990     types, etc.); also a few basic management operations (Theory.copy,
  3991     Theory.merge, etc.)
  3992 
  3993 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  3994 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  3995 for convenience -- they merely return the theory.
  3996 
  3997 * Pure: type Type.tsig is superceded by theory in most interfaces.
  3998 
  3999 * Pure: the Isar proof context type is already defined early in Pure
  4000 as Context.proof (note that ProofContext.context and Proof.context are
  4001 aliases, where the latter is the preferred name).  This enables other
  4002 Isabelle components to refer to that type even before Isar is present.
  4003 
  4004 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  4005 typeK, constK, axiomK, oracleK), but provide explicit operations for
  4006 any of these kinds.  For example, Sign.intern typeK is now
  4007 Sign.intern_type, Theory.hide_space Sign.typeK is now
  4008 Theory.hide_types.  Also note that former
  4009 Theory.hide_classes/types/consts are now
  4010 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  4011 internalize their arguments!  INCOMPATIBILITY.
  4012 
  4013 * Pure: get_thm interface (of PureThy and ProofContext) expects
  4014 datatype thmref (with constructors Name and NameSelection) instead of
  4015 plain string -- INCOMPATIBILITY;
  4016 
  4017 * Pure: cases produced by proof methods specify options, where NONE
  4018 means to remove case bindings -- INCOMPATIBILITY in
  4019 (RAW_)METHOD_CASES.
  4020 
  4021 * Pure: the following operations retrieve axioms or theorems from a
  4022 theory node or theory hierarchy, respectively:
  4023 
  4024   Theory.axioms_of: theory -> (string * term) list
  4025   Theory.all_axioms_of: theory -> (string * term) list
  4026   PureThy.thms_of: theory -> (string * thm) list
  4027   PureThy.all_thms_of: theory -> (string * thm) list
  4028 
  4029 * Pure: print_tac now outputs the goal through the trace channel.
  4030 
  4031 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  4032 Reference Toplevel.debug (default false) controls detailed printing
  4033 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  4034 controls execution profiling -- set to 1 for time and 2 for space
  4035 (both increase the runtime).
  4036 
  4037 * Isar session: The initial use of ROOT.ML is now always timed,
  4038 i.e. the log will show the actual process times, in contrast to the
  4039 elapsed wall-clock time that the outer shell wrapper produces.
  4040 
  4041 * Simplifier: improved handling of bound variables (nameless
  4042 representation, avoid allocating new strings).  Simprocs that invoke
  4043 the Simplifier recursively should use Simplifier.inherit_bounds to
  4044 avoid local name clashes.  Failure to do so produces warnings
  4045 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  4046 for further details.
  4047 
  4048 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  4049 bindings for all theorems stored within a given theory; this may help
  4050 in porting non-Isar theories to Isar ones, while keeping ML proof
  4051 scripts for the time being.
  4052 
  4053 * ML operator HTML.with_charset specifies the charset begin used for
  4054 generated HTML files.  For example:
  4055 
  4056   HTML.with_charset "utf-8" use_thy "Hebrew";
  4057   HTML.with_charset "utf-8" use_thy "Chinese";
  4058 
  4059 
  4060 *** System ***
  4061 
  4062 * Allow symlinks to all proper Isabelle executables (Isabelle,
  4063 isabelle, isatool etc.).
  4064 
  4065 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  4066 isatool doc, isatool mkdir, display_drafts etc.).
  4067 
  4068 * isatool usedir: option -f allows specification of the ML file to be
  4069 used by Isabelle; default is ROOT.ML.
  4070 
  4071 * New isatool version outputs the version identifier of the Isabelle
  4072 distribution being used.
  4073 
  4074 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  4075 (containing Boolean satisfiability problems) into Isabelle/HOL
  4076 theories.
  4077 
  4078 
  4079 
  4080 New in Isabelle2004 (April 2004)
  4081 --------------------------------
  4082 
  4083 *** General ***
  4084 
  4085 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  4086   Replaces linorder.ML.
  4087 
  4088 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  4089   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  4090   (\<a>...\<z>), are now considered normal letters, and can therefore
  4091   be used anywhere where an ASCII letter (a...zA...Z) has until
  4092   now. COMPATIBILITY: This obviously changes the parsing of some
  4093   terms, especially where a symbol has been used as a binder, say
  4094   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  4095   as an identifier.  Fix it by inserting a space around former
  4096   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  4097   existing theory and ML files.
  4098 
  4099 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  4100 
  4101 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  4102   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  4103   a normal (but invisible) letter. For multiple letter subscripts repeat
  4104   \<^isub> like this: x\<^isub>1\<^isub>2.
  4105 
  4106 * Pure: There are now sub-/superscripts that can span more than one
  4107   character. Text between \<^bsub> and \<^esub> is set in subscript in
  4108   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  4109   superscript. The new control characters are not identifier parts.
  4110 
  4111 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  4112   content of "..." to the latex file instead of \isacntrl... . The "..."
  4113   may consist of any printable characters excluding the end bracket >.
  4114 
  4115 * Pure: Using new Isar command "finalconsts" (or the ML functions
  4116   Theory.add_finals or Theory.add_finals_i) it is now possible to
  4117   declare constants "final", which prevents their being given a definition
  4118   later.  It is useful for constants whose behaviour is fixed axiomatically
  4119   rather than definitionally, such as the meta-logic connectives.
  4120 
  4121 * Pure: 'instance' now handles general arities with general sorts
  4122   (i.e. intersections of classes),
  4123 
  4124 * Presentation: generated HTML now uses a CSS style sheet to make layout
  4125   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  4126   It can be changed to alter the colors/layout of generated pages.
  4127 
  4128 
  4129 *** Isar ***
  4130 
  4131 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  4132   cut_tac, subgoal_tac and thin_tac:
  4133   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  4134     locales are no longer forced to write Isar proof scripts.
  4135     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  4136     emulations.
  4137   - INCOMPATIBILITY: names of variables to be instantiated may no
  4138     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  4139     This is consistent with the instantiation attribute "where".
  4140 
  4141 * Attributes "where" and "of":
  4142   - Now take type variables of instantiated theorem into account when reading
  4143     the instantiation string.  This fixes a bug that caused instantiated
  4144     theorems to have too special types in some circumstances.
  4145   - "where" permits explicit instantiations of type variables.
  4146 
  4147 * Calculation commands "moreover" and "also" no longer interfere with
  4148   current facts ("this"), admitting arbitrary combinations with "then"
  4149   and derived forms.
  4150 
  4151 * Locales:
  4152   - Goal statements involving the context element "includes" no longer
  4153     generate theorems with internal delta predicates (those ending on
  4154     "_axioms") in the premise.
  4155     Resolve particular premise with <locale>.intro to obtain old form.
  4156   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  4157     specification and "includes" elements in goal statement.
  4158   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  4159     [intro?] and [elim?] (respectively) by default.
  4160   - Experimental command for instantiation of locales in proof contexts:
  4161         instantiate <label>[<attrs>]: <loc>
  4162     Instantiates locale <loc> and adds all its theorems to the current context
  4163     taking into account their attributes.  Label and attrs are optional
  4164     modifiers, like in theorem declarations.  If present, names of
  4165     instantiated theorems are qualified with <label>, and the attributes
  4166     <attrs> are applied after any attributes these theorems might have already.
  4167       If the locale has assumptions, a chained fact of the form
  4168     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  4169     are derived.  The command does not support old-style locales declared
  4170     with "locale (open)".
  4171       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  4172 
  4173 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  4174   (Isar) contexts.
  4175 
  4176 
  4177 *** HOL ***
  4178 
  4179 * Proof import: new image HOL4 contains the imported library from
  4180   the HOL4 system with about 2500 theorems. It is imported by
  4181   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  4182   can be used like any other Isabelle image.  See
  4183   HOL/Import/HOL/README for more information.
  4184 
  4185 * Simplifier:
  4186   - Much improved handling of linear and partial orders.
  4187     Reasoners for linear and partial orders are set up for type classes
  4188     "linorder" and "order" respectively, and are added to the default simpset
  4189     as solvers.  This means that the simplifier can build transitivity chains
  4190     to solve goals from the assumptions.
  4191   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  4192     of blast or auto after simplification become unnecessary because the goal
  4193     is solved by simplification already.
  4194 
  4195 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  4196     all proved in axiomatic type classes for semirings, rings and fields.
  4197 
  4198 * Numerics:
  4199   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  4200     now formalized using the Ring_and_Field theory mentioned above.
  4201   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  4202     than before, because now they are set up once in a generic manner.
  4203   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  4204     Look for the general versions in Ring_and_Field (and Power if they concern
  4205     exponentiation).
  4206 
  4207 * Type "rat" of the rational numbers is now available in HOL-Complex.
  4208 
  4209 * Records:
  4210   - Record types are now by default printed with their type abbreviation
  4211     instead of the list of all field types. This can be configured via
  4212     the reference "print_record_type_abbr".
  4213   - Simproc "record_upd_simproc" for simplification of multiple updates added
  4214     (not enabled by default).
  4215   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  4216     EX x. x = sel r to True (not enabled by default).
  4217   - Tactic "record_split_simp_tac" to split and simplify records added.
  4218 
  4219 * 'specification' command added, allowing for definition by
  4220   specification.  There is also an 'ax_specification' command that
  4221   introduces the new constants axiomatically.
  4222 
  4223 * arith(_tac) is now able to generate counterexamples for reals as well.
  4224 
  4225 * HOL-Algebra: new locale "ring" for non-commutative rings.
  4226 
  4227 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  4228   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  4229 
  4230 * HOL-Matrix: a first theory for matrices in HOL with an application of
  4231   matrix theory to linear programming.
  4232 
  4233 * Unions and Intersections:
  4234   The latex output syntax of UN and INT has been changed
  4235   from "\Union x \in A. B" to "\Union_{x \in A} B"
  4236   i.e. the index formulae has become a subscript.
  4237   Similarly for "\Union x. B", and for \Inter instead of \Union.
  4238 
  4239 * Unions and Intersections over Intervals:
  4240   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  4241   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  4242   like in normal math, and corresponding versions for < and for intersection.
  4243 
  4244 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  4245   lexicographic dictonary ordering has been added as "lexord".
  4246 
  4247 * ML: the legacy theory structures Int and List have been removed. They had
  4248   conflicted with ML Basis Library structures having the same names.
  4249 
  4250 * 'refute' command added to search for (finite) countermodels.  Only works
  4251   for a fragment of HOL.  The installation of an external SAT solver is
  4252   highly recommended.  See "HOL/Refute.thy" for details.
  4253 
  4254 * 'quickcheck' command: Allows to find counterexamples by evaluating
  4255   formulae under an assignment of free variables to random values.
  4256   In contrast to 'refute', it can deal with inductive datatypes,
  4257   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  4258   for examples.
  4259 
  4260 
  4261 *** HOLCF ***
  4262 
  4263 * Streams now come with concatenation and are part of the HOLCF image
  4264 
  4265 
  4266 
  4267 New in Isabelle2003 (May 2003)
  4268 ------------------------------
  4269 
  4270 *** General ***
  4271 
  4272 * Provers/simplifier:
  4273 
  4274   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  4275     Assumptions are now subject to complete mutual simplification,
  4276     not just from left to right. The simplifier now preserves
  4277     the order of assumptions.
  4278 
  4279     Potential INCOMPATIBILITY:
  4280 
  4281     -- simp sometimes diverges where the old version did
  4282        not, e.g. invoking simp on the goal
  4283 
  4284         [| P (f x); y = x; f x = f y |] ==> Q
  4285 
  4286        now gives rise to the infinite reduction sequence
  4287 
  4288         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  4289 
  4290        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  4291        kind of problem.
  4292 
  4293     -- Tactics combining classical reasoner and simplification (such as auto)
  4294        are also affected by this change, because many of them rely on
  4295        simp. They may sometimes diverge as well or yield a different numbers
  4296        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  4297        in case of problems. Sometimes subsequent calls to the classical
  4298        reasoner will fail because a preceeding call to the simplifier too
  4299        eagerly simplified the goal, e.g. deleted redundant premises.
  4300 
  4301   - The simplifier trace now shows the names of the applied rewrite rules
  4302 
  4303   - You can limit the number of recursive invocations of the simplifier
  4304     during conditional rewriting (where the simplifie tries to solve the
  4305     conditions before applying the rewrite rule):
  4306     ML "simp_depth_limit := n"
  4307     where n is an integer. Thus you can force termination where previously
  4308     the simplifier would diverge.
  4309 
  4310   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  4311 
  4312   - No longer aborts on failed congruence proof.  Instead, the
  4313     congruence is ignored.
  4314 
  4315 * Pure: New generic framework for extracting programs from constructive
  4316   proofs. See HOL/Extraction.thy for an example instantiation, as well
  4317   as HOL/Extraction for some case studies.
  4318 
  4319 * Pure: The main goal of the proof state is no longer shown by default, only
  4320 the subgoals. This behaviour is controlled by a new flag.
  4321    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  4322 (ML: Proof.show_main_goal).
  4323 
  4324 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  4325 rules whose conclusion matches subgoal 1:
  4326       PG menu: Isabelle/Isar -> Show me -> matching rules
  4327 The rules are ordered by how closely they match the subgoal.
  4328 In particular, rules that solve a subgoal outright are displayed first
  4329 (or rather last, the way they are printed).
  4330 (ML: ProofGeneral.print_intros())
  4331 
  4332 * Pure: New flag trace_unify_fail causes unification to print
  4333 diagnostic information (PG: in trace buffer) when it fails. This is
  4334 useful for figuring out why single step proofs like rule, erule or
  4335 assumption failed.
  4336 
  4337 * Pure: Locale specifications now produce predicate definitions
  4338 according to the body of text (covering assumptions modulo local
  4339 definitions); predicate "loc_axioms" covers newly introduced text,
  4340 while "loc" is cumulative wrt. all included locale expressions; the
  4341 latter view is presented only on export into the global theory
  4342 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  4343 on the old view without predicates;
  4344 
  4345 * Pure: predefined locales "var" and "struct" are useful for sharing
  4346 parameters (as in CASL, for example); just specify something like
  4347 ``var x + var y + struct M'' as import;
  4348 
  4349 * Pure: improved thms_containing: proper indexing of facts instead of
  4350 raw theorems; check validity of results wrt. current name space;
  4351 include local facts of proof configuration (also covers active
  4352 locales), cover fixed variables in index; may use "_" in term
  4353 specification; an optional limit for the number of printed facts may
  4354 be given (the default is 40);
  4355 
  4356 * Pure: disallow duplicate fact bindings within new-style theory files
  4357 (batch-mode only);
  4358 
  4359 * Provers: improved induct method: assumptions introduced by case
  4360 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  4361 the goal statement); "foo" still refers to all facts collectively;
  4362 
  4363 * Provers: the function blast.overloaded has been removed: all constants
  4364 are regarded as potentially overloaded, which improves robustness in exchange
  4365 for slight decrease in efficiency;
  4366 
  4367 * Provers/linorder: New generic prover for transitivity reasoning over
  4368 linear orders.  Note: this prover is not efficient!
  4369 
  4370 * Isar: preview of problems to finish 'show' now produce an error
  4371 rather than just a warning (in interactive mode);
  4372 
  4373 
  4374 *** HOL ***
  4375 
  4376 * arith(_tac)
  4377 
  4378  - Produces a counter example if it cannot prove a goal.
  4379    Note that the counter example may be spurious if the goal is not a formula
  4380    of quantifier-free linear arithmetic.
  4381    In ProofGeneral the counter example appears in the trace buffer.
  4382 
  4383  - Knows about div k and mod k where k is a numeral of type nat or int.
  4384 
  4385  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  4386    linear arithmetic fails. This takes account of quantifiers and divisibility.
  4387    Presburger arithmetic can also be called explicitly via presburger(_tac).
  4388 
  4389 * simp's arithmetic capabilities have been enhanced a bit: it now
  4390 takes ~= in premises into account (by performing a case split);
  4391 
  4392 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  4393 are distributed over a sum of terms;
  4394 
  4395 * New tactic "trans_tac" and method "trans" instantiate
  4396 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  4397 "<=", "<" and "=").
  4398 
  4399 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  4400 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  4401 
  4402 * 'typedef' command has new option "open" to suppress the set
  4403 definition;
  4404 
  4405 * functions Min and Max on finite sets have been introduced (theory
  4406 Finite_Set);
  4407 
  4408 * attribute [symmetric] now works for relations as well; it turns
  4409 (x,y) : R^-1 into (y,x) : R, and vice versa;
  4410 
  4411 * induct over a !!-quantified statement (say !!x1..xn):
  4412   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  4413 
  4414 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  4415 %x. None. Warning: empty_def now refers to the previously hidden definition
  4416 of the empty set.
  4417 
  4418 * Algebra: formalization of classical algebra.  Intended as base for
  4419 any algebraic development in Isabelle.  Currently covers group theory
  4420 (up to Sylow's theorem) and ring theory (Universal Property of
  4421 Univariate Polynomials).  Contributions welcome;
  4422 
  4423 * GroupTheory: deleted, since its material has been moved to Algebra;
  4424 
  4425 * Complex: new directory of the complex numbers with numeric constants,
  4426 nonstandard complex numbers, and some complex analysis, standard and
  4427 nonstandard (Jacques Fleuriot);
  4428 
  4429 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  4430 
  4431 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  4432 Fleuriot);
  4433 
  4434 * Real/HahnBanach: updated and adapted to locales;
  4435 
  4436 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  4437 Gray and Kramer);
  4438 
  4439 * UNITY: added the Meier-Sanders theory of progress sets;
  4440 
  4441 * MicroJava: bytecode verifier and lightweight bytecode verifier
  4442 as abstract algorithms, instantiated to the JVM;
  4443 
  4444 * Bali: Java source language formalization. Type system, operational
  4445 semantics, axiomatic semantics. Supported language features:
  4446 classes, interfaces, objects,virtual methods, static methods,
  4447 static/instance fields, arrays, access modifiers, definite
  4448 assignment, exceptions.
  4449 
  4450 
  4451 *** ZF ***
  4452 
  4453 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  4454 universe, etc.);
  4455 
  4456 * Main ZF: virtually all theories converted to new-style format;
  4457 
  4458 
  4459 *** ML ***
  4460 
  4461 * Pure: Tactic.prove provides sane interface for internal proofs;
  4462 omits the infamous "standard" operation, so this is more appropriate
  4463 than prove_goalw_cterm in many situations (e.g. in simprocs);
  4464 
  4465 * Pure: improved error reporting of simprocs;
  4466 
  4467 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  4468 up simprocs;
  4469 
  4470 
  4471 *** Document preparation ***
  4472 
  4473 * uses \par instead of \\ for line breaks in theory text. This may
  4474 shift some page breaks in large documents. To get the old behaviour
  4475 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  4476 
  4477 * minimized dependencies of isabelle.sty and isabellesym.sty on
  4478 other packages
  4479 
  4480 * \<euro> now needs package babel/greek instead of marvosym (which
  4481 broke \Rightarrow)
  4482 
  4483 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  4484 textcomp package)
  4485 
  4486 
  4487 
  4488 New in Isabelle2002 (March 2002)
  4489 --------------------------------
  4490 
  4491 *** Document preparation ***
  4492 
  4493 * greatly simplified document preparation setup, including more
  4494 graceful interpretation of isatool usedir -i/-d/-D options, and more
  4495 instructive isatool mkdir; users should basically be able to get
  4496 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  4497 users may run a separate document processing stage manually like this:
  4498 "isatool usedir -D output HOL Test && isatool document Test/output";
  4499 
  4500 * theory dependency graph may now be incorporated into documents;
  4501 isatool usedir -g true will produce session_graph.eps/.pdf for use
  4502 with \includegraphics of LaTeX;
  4503 
  4504 * proper spacing of consecutive markup elements, especially text
  4505 blocks after section headings;
  4506 
  4507 * support bold style (for single symbols only), input syntax is like
  4508 this: "\<^bold>\<alpha>" or "\<^bold>A";
  4509 
  4510 * \<bullet> is now output as bold \cdot by default, which looks much
  4511 better in printed text;
  4512 
  4513 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  4514 note that these symbols are currently unavailable in Proof General /
  4515 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  4516 
  4517 * isatool latex no longer depends on changed TEXINPUTS, instead
  4518 isatool document copies the Isabelle style files to the target
  4519 location;
  4520 
  4521 
  4522 *** Isar ***
  4523 
  4524 * Pure/Provers: improved proof by cases and induction;
  4525   - 'case' command admits impromptu naming of parameters (such as
  4526     "case (Suc n)");
  4527   - 'induct' method divinates rule instantiation from the inductive
  4528     claim; no longer requires excessive ?P bindings for proper
  4529     instantiation of cases;
  4530   - 'induct' method properly enumerates all possibilities of set/type
  4531     rules; as a consequence facts may be also passed through *type*
  4532     rules without further ado;
  4533   - 'induct' method now derives symbolic cases from the *rulified*
  4534     rule (before it used to rulify cases stemming from the internal
  4535     atomized version); this means that the context of a non-atomic
  4536     statement becomes is included in the hypothesis, avoiding the
  4537     slightly cumbersome show "PROP ?case" form;
  4538   - 'induct' may now use elim-style induction rules without chaining
  4539     facts, using ``missing'' premises from the goal state; this allows
  4540     rules stemming from inductive sets to be applied in unstructured
  4541     scripts, while still benefitting from proper handling of non-atomic
  4542     statements; NB: major inductive premises need to be put first, all
  4543     the rest of the goal is passed through the induction;
  4544   - 'induct' proper support for mutual induction involving non-atomic
  4545     rule statements (uses the new concept of simultaneous goals, see
  4546     below);
  4547   - append all possible rule selections, but only use the first
  4548     success (no backtracking);
  4549   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  4550   - undeclared rule case names default to numbers 1, 2, 3, ...;
  4551   - added 'print_induct_rules' (covered by help item in recent Proof
  4552     General versions);
  4553   - moved induct/cases attributes to Pure, methods to Provers;
  4554   - generic method setup instantiated for FOL and HOL;
  4555 
  4556 * Pure: support multiple simultaneous goal statements, for example
  4557 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  4558 meta-level mechanism, this acts as if several individual goals had
  4559 been stated separately; in particular common proof methods need to be
  4560 repeated in order to cover all claims; note that a single elimination
  4561 step is *not* sufficient to establish the two conjunctions, so this
  4562 fails:
  4563 
  4564   assume "A & B" then have A and B ..   (*".." fails*)
  4565 
  4566 better use "obtain" in situations as above; alternative refer to
  4567 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  4568 
  4569 * Pure: proper integration with ``locales''; unlike the original
  4570 version by Florian Kammller, Isar locales package high-level proof
  4571 contexts rather than raw logical ones (e.g. we admit to include
  4572 attributes everywhere); operations on locales include merge and
  4573 rename; support for implicit arguments (``structures''); simultaneous
  4574 type-inference over imports and text; see also HOL/ex/Locales.thy for
  4575 some examples;
  4576 
  4577 * Pure: the following commands have been ``localized'', supporting a
  4578 target locale specification "(in name)": 'lemma', 'theorem',
  4579 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  4580 stored both within the locale and at the theory level (exported and
  4581 qualified by the locale name);
  4582 
  4583 * Pure: theory goals may now be specified in ``long'' form, with
  4584 ad-hoc contexts consisting of arbitrary locale elements. for example
  4585 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  4586 definitions may be given, too); the result is a meta-level rule with
  4587 the context elements being discharged in the obvious way;
  4588 
  4589 * Pure: new proof command 'using' allows to augment currently used
  4590 facts after a goal statement ('using' is syntactically analogous to
  4591 'apply', but acts on the goal's facts only); this allows chained facts
  4592 to be separated into parts given before and after a claim, as in
  4593 ``from a and b have C using d and e <proof>'';
  4594 
  4595 * Pure: renamed "antecedent" case to "rule_context";
  4596 
  4597 * Pure: new 'judgment' command records explicit information about the
  4598 object-logic embedding (used by several tools internally); no longer
  4599 use hard-wired "Trueprop";
  4600 
  4601 * Pure: added 'corollary' command;
  4602 
  4603 * Pure: fixed 'token_translation' command;
  4604 
  4605 * Pure: removed obsolete 'exported' attribute;
  4606 
  4607 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  4608 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  4609 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  4610 
  4611 * Pure: method 'atomize' presents local goal premises as object-level
  4612 statements (atomic meta-level propositions); setup controlled via
  4613 rewrite rules declarations of 'atomize' attribute; example
  4614 application: 'induct' method with proper rule statements in improper
  4615 proof *scripts*;
  4616 
  4617 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  4618 now consider the syntactic context of assumptions, giving a better
  4619 chance to get type-inference of the arguments right (this is
  4620 especially important for locales);
  4621 
  4622 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  4623 mode;
  4624 
  4625 * Pure/obtain: the formal conclusion "thesis", being marked as
  4626 ``internal'', may no longer be reference directly in the text;
  4627 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  4628 situations;
  4629 
  4630 * Pure: generic 'sym' attribute which declares a rule both as pure
  4631 'elim?' and for the 'symmetric' operation;
  4632 
  4633 * Pure: marginal comments ``--'' may now occur just anywhere in the
  4634 text; the fixed correlation with particular command syntax has been
  4635 discontinued;
  4636 
  4637 * Pure: new method 'rules' is particularly well-suited for proof
  4638 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  4639 but often produces more compact proof terms with less detours;
  4640 
  4641 * Pure/Provers/classical: simplified integration with pure rule
  4642 attributes and methods; the classical "intro?/elim?/dest?"
  4643 declarations coincide with the pure ones; the "rule" method no longer
  4644 includes classically swapped intros; "intro" and "elim" methods no
  4645 longer pick rules from the context; also got rid of ML declarations
  4646 AddXIs/AddXEs/AddXDs; all of this has some potential for
  4647 INCOMPATIBILITY;
  4648 
  4649 * Provers/classical: attribute 'swapped' produces classical inversions
  4650 of introduction rules;
  4651 
  4652 * Provers/simplifier: 'simplified' attribute may refer to explicit
  4653 rules instead of full simplifier context; 'iff' attribute handles
  4654 conditional rules;
  4655 
  4656 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  4657 
  4658 * HOL: 'recdef' now fails on unfinished automated proofs, use
  4659 "(permissive)" option to recover old behavior;
  4660 
  4661 * HOL: 'inductive' no longer features separate (collective) attributes
  4662 for 'intros' (was found too confusing);
  4663 
  4664 * HOL: properly declared induction rules less_induct and
  4665 wf_induct_rule;
  4666 
  4667 
  4668 *** HOL ***
  4669 
  4670 * HOL: moved over to sane numeral syntax; the new policy is as
  4671 follows:
  4672 
  4673   - 0 and 1 are polymorphic constants, which are defined on any
  4674   numeric type (nat, int, real etc.);
  4675 
  4676   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  4677   binary representation internally;
  4678 
  4679   - type nat has special constructor Suc, and generally prefers Suc 0
  4680   over 1::nat and Suc (Suc 0) over 2::nat;
  4681 
  4682 This change may cause significant problems of INCOMPATIBILITY; here
  4683 are some hints on converting existing sources:
  4684 
  4685   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  4686   entities, so expressions involving "-" (unary or binary minus) need
  4687   to be spaced properly;
  4688 
  4689   - existing occurrences of "1" may need to be constraint "1::nat" or
  4690   even replaced by Suc 0; similar for old "2";
  4691 
  4692   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  4693 
  4694   - remove all special provisions on numerals in proofs;
  4695 
  4696 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  4697 representation (depends on bin_arith_simps in the default context);
  4698 
  4699 * HOL: symbolic syntax for x^2 (numeral 2);
  4700 
  4701 * HOL: the class of all HOL types is now called "type" rather than
  4702 "term"; INCOMPATIBILITY, need to adapt references to this type class
  4703 in axclass/classes, instance/arities, and (usually rare) occurrences
  4704 in typings (of consts etc.); internally the class is called
  4705 "HOL.type", ML programs should refer to HOLogic.typeS;
  4706 
  4707 * HOL/record package improvements:
  4708   - new derived operations "fields" to build a partial record section,
  4709     "extend" to promote a fixed record to a record scheme, and
  4710     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  4711     declared as simp by default;
  4712   - shared operations ("more", "fields", etc.) now need to be always
  4713     qualified) --- potential INCOMPATIBILITY;
  4714   - removed "make_scheme" operations (use "make" with "extend") --
  4715     INCOMPATIBILITY;
  4716   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  4717   - provides cases/induct rules for use with corresponding Isar
  4718     methods (for concrete records, record schemes, concrete more
  4719     parts, and schematic more parts -- in that order);
  4720   - internal definitions directly based on a light-weight abstract
  4721     theory of product types over typedef rather than datatype;
  4722 
  4723 * HOL: generic code generator for generating executable ML code from
  4724 specifications; specific support for HOL constructs such as inductive
  4725 datatypes and sets, as well as recursive functions; can be invoked
  4726 via 'generate_code' theory section;
  4727 
  4728 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  4729 
  4730 * HOL: consolidated and renamed several theories.  In particular:
  4731         Ord.thy has been absorbed into HOL.thy
  4732         String.thy has been absorbed into List.thy
  4733 
  4734 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  4735 (beware of argument permutation!);
  4736 
  4737 * HOL: linorder_less_split superseded by linorder_cases;
  4738 
  4739 * HOL/List: "nodups" renamed to "distinct";
  4740 
  4741 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  4742 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  4743   - Ex_def has changed, now need to use some_eq_ex
  4744 
  4745 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  4746 in this (rare) case use:
  4747 
  4748   delSWrapper "split_all_tac"
  4749   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  4750 
  4751 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  4752 MAY FAIL;
  4753 
  4754 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  4755 Isabelle's type classes, ^ on functions and relations has too general
  4756 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  4757 necessary to attach explicit type constraints;
  4758 
  4759 * HOL/Relation: the prefix name of the infix "O" has been changed from
  4760 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  4761 renamed accordingly (eg "compI" -> "rel_compI").
  4762 
  4763 * HOL: syntax translations now work properly with numerals and records
  4764 expressions;
  4765 
  4766 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  4767 of "lam" -- INCOMPATIBILITY;
  4768 
  4769 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  4770 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  4771 renamed "Product_Type.unit";
  4772 
  4773 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  4774 
  4775 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  4776 the "cases" method);
  4777 
  4778 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  4779 Florian Kammller);
  4780 
  4781 * HOL/IMP: updated and converted to new-style theory format; several
  4782 parts turned into readable document, with proper Isar proof texts and
  4783 some explanations (by Gerwin Klein);
  4784 
  4785 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  4786 
  4787 * HOL-Hyperreal is now a logic image;
  4788 
  4789 
  4790 *** HOLCF ***
  4791 
  4792 * Isar: consts/constdefs supports mixfix syntax for continuous
  4793 operations;
  4794 
  4795 * Isar: domain package adapted to new-style theory format, e.g. see
  4796 HOLCF/ex/Dnat.thy;
  4797 
  4798 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  4799 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  4800 lift.induct_tac, always use UU instead of Undef;
  4801 
  4802 * HOLCF/IMP: updated and converted to new-style theory;
  4803 
  4804 
  4805 *** ZF ***
  4806 
  4807 * Isar: proper integration of logic-specific tools and packages,
  4808 including theory commands '(co)inductive', '(co)datatype',
  4809 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  4810 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  4811 
  4812 * theory Main no longer includes AC; for the Axiom of Choice, base
  4813 your theory on Main_ZFC;
  4814 
  4815 * the integer library now covers quotients and remainders, with many
  4816 laws relating division to addition, multiplication, etc.;
  4817 
  4818 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  4819 typeless version of the formalism;
  4820 
  4821 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  4822 format;
  4823 
  4824 * ZF/Induct: new directory for examples of inductive definitions,
  4825 including theory Multiset for multiset orderings; converted to
  4826 new-style theory format;
  4827 
  4828 * ZF: many new theorems about lists, ordinals, etc.;
  4829 
  4830 
  4831 *** General ***
  4832 
  4833 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  4834 variable proof controls level of detail: 0 = no proofs (only oracle
  4835 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  4836 also ref manual for further ML interfaces;
  4837 
  4838 * Pure/axclass: removed obsolete ML interface
  4839 goal_subclass/goal_arity;
  4840 
  4841 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  4842 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  4843 separate tokens, so expressions involving minus need to be spaced
  4844 properly;
  4845 
  4846 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  4847 rather than "infixl" or "infixr";
  4848 
  4849 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  4850 sort constraint specifications in type inference; e.g. "x::_::foo"
  4851 ensures that the type of "x" is of sort "foo" (but not necessarily a
  4852 type variable);
  4853 
  4854 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  4855 control output of nested => (types); the default behavior is
  4856 "type_brackets";
  4857 
  4858 * Pure/syntax: builtin parse translation for "_constify" turns valued
  4859 tokens into AST constants;
  4860 
  4861 * Pure/syntax: prefer later declarations of translations and print
  4862 translation functions; potential INCOMPATIBILITY: need to reverse
  4863 multiple declarations for same syntax element constant;
  4864 
  4865 * Pure/show_hyps reset by default (in accordance to existing Isar
  4866 practice);
  4867 
  4868 * Provers/classical: renamed addaltern to addafter, addSaltern to
  4869 addSafter;
  4870 
  4871 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  4872 as well;
  4873 
  4874 * system: tested support for MacOS X; should be able to get Isabelle +
  4875 Proof General to work in a plain Terminal after installing Poly/ML
  4876 (e.g. from the Isabelle distribution area) and GNU bash alone
  4877 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  4878 support requires further installations, e.g. from
  4879 http://fink.sourceforge.net/);
  4880 
  4881 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  4882 
  4883 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  4884 of 40 MB), cf. ML_OPTIONS;
  4885 
  4886 * system: Proof General keywords specification is now part of the
  4887 Isabelle distribution (see etc/isar-keywords.el);
  4888 
  4889 * system: support for persistent Proof General sessions (refrain from
  4890 outdating all loaded theories on startup); user may create writable
  4891 logic images like this: ``isabelle -q HOL Test'';
  4892 
  4893 * system: smart selection of Isabelle process versus Isabelle
  4894 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  4895 run both "isabelle" and "Isabelle" even if file names are badly
  4896 damaged (executable inspects the case of the first letter of its own
  4897 name); added separate "isabelle-process" and "isabelle-interface";
  4898 
  4899 * system: refrain from any attempt at filtering input streams; no
  4900 longer support ``8bit'' encoding of old isabelle font, instead proper
  4901 iso-latin characters may now be used; the related isatools
  4902 "symbolinput" and "nonascii" have disappeared as well;
  4903 
  4904 * system: removed old "xterm" interface (the print modes "xterm" and
  4905 "xterm_color" are still available for direct use in a suitable
  4906 terminal);
  4907 
  4908 
  4909 
  4910 New in Isabelle99-2 (February 2001)
  4911 -----------------------------------
  4912 
  4913 *** Overview of INCOMPATIBILITIES ***
  4914 
  4915 * HOL: please note that theories in the Library and elsewhere often use the
  4916 new-style (Isar) format; to refer to their theorems in an ML script you must
  4917 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  4918 
  4919 * HOL: inductive package no longer splits induction rule aggressively,
  4920 but only as far as specified by the introductions given; the old
  4921 format may be recovered via ML function complete_split_rule or attribute
  4922 'split_rule (complete)';
  4923 
  4924 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  4925 gfp_Tarski to gfp_unfold;
  4926 
  4927 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  4928 
  4929 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  4930 relation); infix "^^" has been renamed "``"; infix "``" has been
  4931 renamed "`"; "univalent" has been renamed "single_valued";
  4932 
  4933 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  4934 operation;
  4935 
  4936 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  4937 
  4938 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  4939 
  4940 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  4941 consequence, it is no longer monotonic wrt. the local goal context
  4942 (which is now passed through the inductive cases);
  4943 
  4944 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  4945 \<gg> to \<ggreater>;
  4946 
  4947 
  4948 *** Document preparation ***
  4949 
  4950 * \isabellestyle{NAME} selects version of Isabelle output (currently
  4951 available: are "it" for near math-mode best-style output, "sl" for
  4952 slanted text style, and "tt" for plain type-writer; if no
  4953 \isabellestyle command is given, output is according to slanted
  4954 type-writer);
  4955 
  4956 * support sub/super scripts (for single symbols only), input syntax is
  4957 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  4958 
  4959 * some more standard symbols; see Appendix A of the system manual for
  4960 the complete list of symbols defined in isabellesym.sty;
  4961 
  4962 * improved isabelle style files; more abstract symbol implementation
  4963 (should now use \isamath{...} and \isatext{...} in custom symbol
  4964 definitions);
  4965 
  4966 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  4967 state; Note that presentation of goal states does not conform to
  4968 actual human-readable proof documents.  Please do not include goal
  4969 states into document output unless you really know what you are doing!
  4970 
  4971 * proper indentation of antiquoted output with proportional LaTeX
  4972 fonts;
  4973 
  4974 * no_document ML operator temporarily disables LaTeX document
  4975 generation;
  4976 
  4977 * isatool unsymbolize tunes sources for plain ASCII communication;
  4978 
  4979 
  4980 *** Isar ***
  4981 
  4982 * Pure: Isar now suffers initial goal statements to contain unbound
  4983 schematic variables (this does not conform to actual readable proof
  4984 documents, due to unpredictable outcome and non-compositional proof
  4985 checking); users who know what they are doing may use schematic goals
  4986 for Prolog-style synthesis of proven results;
  4987 
  4988 * Pure: assumption method (an implicit finishing) now handles actual
  4989 rules as well;
  4990 
  4991 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  4992 initial goal, declare "that" only as Pure intro (only for single
  4993 steps); the "that" rule assumption may now be involved in implicit
  4994 finishing, thus ".." becomes a feasible for trivial obtains;
  4995 
  4996 * Pure: default proof step now includes 'intro_classes'; thus trivial
  4997 instance proofs may be performed by "..";
  4998 
  4999 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  5000 statements as well;
  5001 
  5002 * Pure: more robust selection of calculational rules;
  5003 
  5004 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  5005 rule (as well as the assumption rule);
  5006 
  5007 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  5008 lemmas, using the graph browser tool;
  5009 
  5010 * Pure: predict failure of "show" in interactive mode;
  5011 
  5012 * Pure: 'thms_containing' now takes actual terms as arguments;
  5013 
  5014 * HOL: improved method 'induct' --- now handles non-atomic goals
  5015 (potential INCOMPATIBILITY); tuned error handling;
  5016 
  5017 * HOL: cases and induct rules now provide explicit hints about the
  5018 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  5019 any remaining facts are inserted into the goal verbatim;
  5020 
  5021 * HOL: local contexts (aka cases) may now contain term bindings as
  5022 well; the 'cases' and 'induct' methods new provide a ?case binding for
  5023 the result to be shown in each case;
  5024 
  5025 * HOL: added 'recdef_tc' command;
  5026 
  5027 * isatool convert assists in eliminating legacy ML scripts;
  5028 
  5029 
  5030 *** HOL ***
  5031 
  5032 * HOL/Library: a collection of generic theories to be used together
  5033 with main HOL; the theory loader path already includes this directory
  5034 by default; the following existing theories have been moved here:
  5035 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  5036 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  5037 
  5038 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  5039 modelling and verification task performed in Isabelle/HOL +
  5040 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  5041 
  5042 * HOL/Algebra: special summation operator SUM no longer exists, it has
  5043 been replaced by setsum; infix 'assoc' now has priority 50 (like
  5044 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  5045 'domain', this makes the theory consistent with mathematical
  5046 literature;
  5047 
  5048 * HOL basics: added overloaded operations "inverse" and "divide"
  5049 (infix "/"), syntax for generic "abs" operation, generic summation
  5050 operator \<Sum>;
  5051 
  5052 * HOL/typedef: simplified package, provide more useful rules (see also
  5053 HOL/subset.thy);
  5054 
  5055 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  5056 now expressed as a proper nested rule (old-style tactic scripts may
  5057 require atomize_strip_tac to cope with non-atomic premises);
  5058 
  5059 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  5060 to "split_conv" (old name still available for compatibility);
  5061 
  5062 * HOL: improved concrete syntax for strings (e.g. allows translation
  5063 rules with string literals);
  5064 
  5065 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  5066  and Fleuriot's mechanization of analysis, including the transcendental
  5067  functions for the reals;
  5068 
  5069 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  5070 
  5071 
  5072 *** CTT ***
  5073 
  5074 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  5075 "lam" is displayed as TWO lambda-symbols
  5076 
  5077 * CTT: theory Main now available, containing everything (that is, Bool
  5078 and Arith);
  5079 
  5080 
  5081 *** General ***
  5082 
  5083 * Pure: the Simplifier has been implemented properly as a derived rule
  5084 outside of the actual kernel (at last!); the overall performance
  5085 penalty in practical applications is about 50%, while reliability of
  5086 the Isabelle inference kernel has been greatly improved;
  5087 
  5088 * print modes "brackets" and "no_brackets" control output of nested =>
  5089 (types) and ==> (props); the default behaviour is "brackets";
  5090 
  5091 * Provers: fast_tac (and friends) now handle actual object-logic rules
  5092 as assumptions as well;
  5093 
  5094 * system: support Poly/ML 4.0;
  5095 
  5096 * system: isatool install handles KDE version 1 or 2;
  5097 
  5098 
  5099 
  5100 New in Isabelle99-1 (October 2000)
  5101 ----------------------------------
  5102 
  5103 *** Overview of INCOMPATIBILITIES ***
  5104 
  5105 * HOL: simplification of natural numbers is much changed; to partly
  5106 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  5107 issue the following ML commands:
  5108 
  5109   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  5110   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  5111 
  5112 * HOL: simplification no longer dives into case-expressions; this is
  5113 controlled by "t.weak_case_cong" for each datatype t;
  5114 
  5115 * HOL: nat_less_induct renamed to less_induct;
  5116 
  5117 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  5118 fixsome to patch .thy and .ML sources automatically;
  5119 
  5120   select_equality  -> some_equality
  5121   select_eq_Ex     -> some_eq_ex
  5122   selectI2EX       -> someI2_ex
  5123   selectI2         -> someI2
  5124   selectI          -> someI
  5125   select1_equality -> some1_equality
  5126   Eps_sym_eq       -> some_sym_eq_trivial
  5127   Eps_eq           -> some_eq_trivial
  5128 
  5129 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  5130 
  5131 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  5132 instead);
  5133 
  5134 * HOL: the recursion equations generated by 'recdef' are now called
  5135 f.simps instead of f.rules;
  5136 
  5137 * HOL: qed_spec_mp now also handles bounded ALL as well;
  5138 
  5139 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  5140 sometimes be needed;
  5141 
  5142 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  5143 
  5144 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  5145 
  5146 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  5147 product is now "<*>" instead of "Times"; the lexicographic product is
  5148 now "<*lex*>" instead of "**";
  5149 
  5150 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  5151 of main HOL, but was unused); better use HOL's datatype package;
  5152 
  5153 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  5154 the old syntax may be recovered as follows:
  5155 
  5156   syntax (symbols)
  5157     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  5158       (infixl "\\<oplus>" 100)
  5159 
  5160 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5161 
  5162 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  5163 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  5164 internally;
  5165 
  5166 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  5167 changed from A/r to A//r;
  5168 
  5169 * ZF: new treatment of arithmetic (nat & int) may break some old
  5170 proofs;
  5171 
  5172 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  5173 rulify -> rule_format, elimify -> elim_format, ...);
  5174 
  5175 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5176 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  5177 should have to change intro!! to intro? only); replaced "delrule" by
  5178 "rule del";
  5179 
  5180 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  5181 
  5182 * Provers: strengthened force_tac by using new first_best_tac;
  5183 
  5184 * LaTeX document preparation: several changes of isabelle.sty (see
  5185 lib/texinputs);
  5186 
  5187 
  5188 *** Document preparation ***
  5189 
  5190 * formal comments (text blocks etc.) in new-style theories may now
  5191 contain antiquotations of thm/prop/term/typ/text to be presented
  5192 according to latex print mode; concrete syntax is like this:
  5193 @{term[show_types] "f(x) = a + x"};
  5194 
  5195 * isatool mkdir provides easy setup of Isabelle session directories,
  5196 including proper document sources;
  5197 
  5198 * generated LaTeX sources are now deleted after successful run
  5199 (isatool document -c); may retain a copy somewhere else via -D option
  5200 of isatool usedir;
  5201 
  5202 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  5203 style files, achieving self-contained LaTeX sources and simplifying
  5204 LaTeX debugging;
  5205 
  5206 * old-style theories now produce (crude) LaTeX output as well;
  5207 
  5208 * browser info session directories are now self-contained (may be put
  5209 on WWW server seperately); improved graphs of nested sessions; removed
  5210 graph for 'all sessions';
  5211 
  5212 * several improvements in isabelle style files; \isabellestyle{it}
  5213 produces fake math mode output; \isamarkupheader is now \section by
  5214 default; see lib/texinputs/isabelle.sty etc.;
  5215 
  5216 
  5217 *** Isar ***
  5218 
  5219 * Isar/Pure: local results and corresponding term bindings are now
  5220 subject to Hindley-Milner polymorphism (similar to ML); this
  5221 accommodates incremental type-inference very nicely;
  5222 
  5223 * Isar/Pure: new derived language element 'obtain' supports
  5224 generalized existence reasoning;
  5225 
  5226 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  5227 support accumulation of results, without applying any rules yet;
  5228 useful to collect intermediate results without explicit name
  5229 references, and for use with transitivity rules with more than 2
  5230 premises;
  5231 
  5232 * Isar/Pure: scalable support for case-analysis type proofs: new
  5233 'case' language element refers to local contexts symbolically, as
  5234 produced by certain proof methods; internally, case names are attached
  5235 to theorems as "tags";
  5236 
  5237 * Isar/Pure: theory command 'hide' removes declarations from
  5238 class/type/const name spaces;
  5239 
  5240 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  5241 indicate potential overloading;
  5242 
  5243 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  5244 
  5245 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  5246 "{a,b,c}" instead of {a,b,c};
  5247 
  5248 * Isar/Pure now provides its own version of intro/elim/dest
  5249 attributes; useful for building new logics, but beware of confusion
  5250 with the version in Provers/classical;
  5251 
  5252 * Isar/Pure: the local context of (non-atomic) goals is provided via
  5253 case name 'antecedent';
  5254 
  5255 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  5256 to the current context is now done automatically);
  5257 
  5258 * Isar/Pure: theory command 'method_setup' provides a simple interface
  5259 for definining proof methods in ML;
  5260 
  5261 * Isar/Provers: intro/elim/dest attributes changed; renamed
  5262 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  5263 most cases, one should have to change intro!! to intro? only);
  5264 replaced "delrule" by "rule del";
  5265 
  5266 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  5267 'symmetric' attribute (the latter supercedes [RS sym]);
  5268 
  5269 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  5270 method modifier); 'simp' method: 'only:' modifier removes loopers as
  5271 well (including splits);
  5272 
  5273 * Isar/Provers: Simplifier and Classical methods now support all kind
  5274 of modifiers used in the past, including 'cong', 'iff', etc.
  5275 
  5276 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  5277 of Simplifier and Classical reasoner);
  5278 
  5279 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  5280 now support named cases; major packages (inductive, datatype, primrec,
  5281 recdef) support case names and properly name parameters;
  5282 
  5283 * Isar/HOL: new transitivity rules for substitution in inequalities --
  5284 monotonicity conditions are extracted to be proven at end of
  5285 calculations;
  5286 
  5287 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  5288 method anyway;
  5289 
  5290 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  5291 split_if split_if_asm; datatype package provides theorems foo.splits =
  5292 foo.split foo.split_asm for each datatype;
  5293 
  5294 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  5295 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  5296 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  5297 use "(cases (simplified))" method in proper proof texts);
  5298 
  5299 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  5300 
  5301 * Isar: names of theorems etc. may be natural numbers as well;
  5302 
  5303 * Isar: 'pr' command: optional arguments for goals_limit and
  5304 ProofContext.prems_limit; no longer prints theory contexts, but only
  5305 proof states;
  5306 
  5307 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  5308 additional print modes to be specified; e.g. "pr(latex)" will print
  5309 proof state according to the Isabelle LaTeX style;
  5310 
  5311 * Isar: improved support for emulating tactic scripts, including proof
  5312 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  5313 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  5314 (for HOL datatypes);
  5315 
  5316 * Isar: simplified (more robust) goal selection of proof methods: 1st
  5317 goal, all goals, or explicit goal specifier (tactic emulation); thus
  5318 'proof method scripts' have to be in depth-first order;
  5319 
  5320 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  5321 
  5322 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  5323 should instead use individual commands for printing items
  5324 (print_commands, print_methods etc.);
  5325 
  5326 * Isar: added 'nothing' --- the empty list of theorems;
  5327 
  5328 
  5329 *** HOL ***
  5330 
  5331 * HOL/MicroJava: formalization of a fragment of Java, together with a
  5332 corresponding virtual machine and a specification of its bytecode
  5333 verifier and a lightweight bytecode verifier, including proofs of
  5334 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  5335 Cornelia Pusch (see also the homepage of project Bali at
  5336 http://isabelle.in.tum.de/Bali/);
  5337 
  5338 * HOL/Algebra: new theory of rings and univariate polynomials, by
  5339 Clemens Ballarin;
  5340 
  5341 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  5342 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  5343 Rasmussen;
  5344 
  5345 * HOL/Lattice: fundamental concepts of lattice theory and order
  5346 structures, including duals, properties of bounds versus algebraic
  5347 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  5348 Theorem for complete lattices etc.; may also serve as a demonstration
  5349 for abstract algebraic reasoning using axiomatic type classes, and
  5350 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  5351 
  5352 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  5353 von Oheimb;
  5354 
  5355 * HOL/IMPP: extension of IMP with local variables and mutually
  5356 recursive procedures, by David von Oheimb;
  5357 
  5358 * HOL/Lambda: converted into new-style theory and document;
  5359 
  5360 * HOL/ex/Multiquote: example of multiple nested quotations and
  5361 anti-quotations -- basically a generalized version of de-Bruijn
  5362 representation; very useful in avoiding lifting of operations;
  5363 
  5364 * HOL/record: added general record equality rule to simpset; fixed
  5365 select-update simplification procedure to handle extended records as
  5366 well; admit "r" as field name;
  5367 
  5368 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  5369 other numeric types and also as the identity of groups, rings, etc.;
  5370 
  5371 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  5372 Types nat and int belong to this axclass;
  5373 
  5374 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  5375    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  5376    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  5377   two terms #m*u and #n*u are replaced by #(m+n)*u
  5378     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  5379   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  5380     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  5381 
  5382 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  5383 powerful prover for predicate logic but knows nothing of clasets; see
  5384 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  5385 
  5386 * HOL: new version of "case_tac" subsumes both boolean case split and
  5387 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  5388 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  5389 
  5390 * HOL: simplification no longer dives into case-expressions: only the
  5391 selector expression is simplified, but not the remaining arms; to
  5392 enable full simplification of case-expressions for datatype t, you may
  5393 remove t.weak_case_cong from the simpset, either globally (Delcongs
  5394 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  5395 
  5396 * HOL/recdef: the recursion equations generated by 'recdef' for
  5397 function 'f' are now called f.simps instead of f.rules; if all
  5398 termination conditions are proved automatically, these simplification
  5399 rules are added to the simpset, as in primrec; rules may be named
  5400 individually as well, resulting in a separate list of theorems for
  5401 each equation;
  5402 
  5403 * HOL/While is a new theory that provides a while-combinator. It
  5404 permits the definition of tail-recursive functions without the
  5405 provision of a termination measure. The latter is necessary once the
  5406 invariant proof rule for while is applied.
  5407 
  5408 * HOL: new (overloaded) notation for the set of elements below/above
  5409 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  5410 
  5411 * HOL: theorems impI, allI, ballI bound as "strip";
  5412 
  5413 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  5414 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  5415 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  5416 
  5417 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  5418 
  5419 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  5420 main HOL, but was unused);
  5421 
  5422 * HOL: fewer consts declared as global (e.g. have to refer to
  5423 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  5424 
  5425 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  5426 in case of overlap with user translations (e.g. judgements over
  5427 tuples); (note that the underlying logical represenation is still
  5428 bogus);
  5429 
  5430 
  5431 *** ZF ***
  5432 
  5433 * ZF: simplification automatically cancels common terms in arithmetic
  5434 expressions over nat and int;
  5435 
  5436 * ZF: new treatment of nat to minimize type-checking: all operators
  5437 coerce their operands to a natural number using the function natify,
  5438 making the algebraic laws unconditional;
  5439 
  5440 * ZF: as above, for int: operators coerce their operands to an integer
  5441 using the function intify;
  5442 
  5443 * ZF: the integer library now contains many of the usual laws for the
  5444 orderings, including $<=, and monotonicity laws for $+ and $*;
  5445 
  5446 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  5447 simplification;
  5448 
  5449 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  5450 to the simplifier and classical reasoner simultaneously;
  5451 
  5452 
  5453 *** General ***
  5454 
  5455 * Provers: blast_tac now handles actual object-logic rules as
  5456 assumptions; note that auto_tac uses blast_tac internally as well;
  5457 
  5458 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  5459 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  5460 
  5461 * Provers: delrules now handles destruct rules as well (no longer need
  5462 explicit make_elim);
  5463 
  5464 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  5465   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5466 use instead the strong form,
  5467   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  5468 in HOL, FOL and ZF the function cla_make_elim will create such rules
  5469 from destruct-rules;
  5470 
  5471 * Provers: Simplifier.easy_setup provides a fast path to basic
  5472 Simplifier setup for new object-logics;
  5473 
  5474 * Pure: AST translation rules no longer require constant head on LHS;
  5475 
  5476 * Pure: improved name spaces: ambiguous output is qualified; support
  5477 for hiding of names;
  5478 
  5479 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  5480 XSYMBOL_HOME; no longer need to do manual configuration in most
  5481 situations;
  5482 
  5483 * system: compression of ML heaps images may now be controlled via -c
  5484 option of isabelle and isatool usedir (currently only observed by
  5485 Poly/ML);
  5486 
  5487 * system: isatool installfonts may handle X-Symbol fonts as well (very
  5488 useful for remote X11);
  5489 
  5490 * system: provide TAGS file for Isabelle sources;
  5491 
  5492 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  5493 order;
  5494 
  5495 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  5496 timing flag supersedes proof_timing and Toplevel.trace;
  5497 
  5498 * ML: new combinators |>> and |>>> for incremental transformations
  5499 with secondary results (e.g. certain theory extensions):
  5500 
  5501 * ML: PureThy.add_defs gets additional argument to indicate potential
  5502 overloading (usually false);
  5503 
  5504 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  5505 results;
  5506 
  5507 
  5508 
  5509 New in Isabelle99 (October 1999)
  5510 --------------------------------
  5511 
  5512 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5513 
  5514 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  5515 are no longer simplified.  (This allows the simplifier to unfold recursive
  5516 functional programs.)  To restore the old behaviour, declare
  5517 
  5518     Delcongs [if_weak_cong];
  5519 
  5520 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  5521 complement;
  5522 
  5523 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  5524 
  5525 * HOL/datatype: mutual_induct_tac no longer exists --
  5526   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  5527 
  5528 * HOL/typedef: fixed type inference for representing set; type
  5529 arguments now have to occur explicitly on the rhs as type constraints;
  5530 
  5531 * ZF: The con_defs part of an inductive definition may no longer refer
  5532 to constants declared in the same theory;
  5533 
  5534 * HOL, ZF: the function mk_cases, generated by the inductive
  5535 definition package, has lost an argument.  To simplify its result, it
  5536 uses the default simpset instead of a supplied list of theorems.
  5537 
  5538 * HOL/List: the constructors of type list are now Nil and Cons;
  5539 
  5540 * Simplifier: the type of the infix ML functions
  5541         setSSolver addSSolver setSolver addSolver
  5542 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  5543 for packaging solvers. A solver is created via
  5544         mk_solver: string -> (thm list -> int -> tactic) -> solver
  5545 where the string argument is only a comment.
  5546 
  5547 
  5548 *** Proof tools ***
  5549 
  5550 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  5551 decision procedure for linear arithmetic. Currently it is used for
  5552 types `nat', `int', and `real' in HOL (see below); it can, should and
  5553 will be instantiated for other types and logics as well.
  5554 
  5555 * The simplifier now accepts rewrite rules with flexible heads, eg
  5556      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  5557   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  5558   matching.
  5559 
  5560 
  5561 *** General ***
  5562 
  5563 * New Isabelle/Isar subsystem provides an alternative to traditional
  5564 tactical theorem proving; together with the ProofGeneral/isar user
  5565 interface it offers an interactive environment for developing human
  5566 readable proof documents (Isar == Intelligible semi-automated
  5567 reasoning); for further information see isatool doc isar-ref,
  5568 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  5569 
  5570 * improved and simplified presentation of theories: better HTML markup
  5571 (including colors), graph views in several sizes; isatool usedir now
  5572 provides a proper interface for user theories (via -P option); actual
  5573 document preparation based on (PDF)LaTeX is available as well (for
  5574 new-style theories only); see isatool doc system for more information;
  5575 
  5576 * native support for Proof General, both for classic Isabelle and
  5577 Isabelle/Isar;
  5578 
  5579 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  5580 using the graph browser tool;
  5581 
  5582 * Isabelle manuals now also available as PDF;
  5583 
  5584 * theory loader rewritten from scratch (may not be fully
  5585 bug-compatible); old loadpath variable has been replaced by show_path,
  5586 add_path, del_path, reset_path functions; new operations such as
  5587 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  5588 isatool doc ref);
  5589 
  5590 * improved isatool install: option -k creates KDE application icon,
  5591 option -p DIR installs standalone binaries;
  5592 
  5593 * added ML_PLATFORM setting (useful for cross-platform installations);
  5594 more robust handling of platform specific ML images for SML/NJ;
  5595 
  5596 * the settings environment is now statically scoped, i.e. it is never
  5597 created again in sub-processes invoked from isabelle, isatool, or
  5598 Isabelle;
  5599 
  5600 * path element specification '~~' refers to '$ISABELLE_HOME';
  5601 
  5602 * in locales, the "assumes" and "defines" parts may be omitted if
  5603 empty;
  5604 
  5605 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  5606 long arrows);
  5607 
  5608 * new print_mode "HTML";
  5609 
  5610 * new flag show_tags controls display of tags of theorems (which are
  5611 basically just comments that may be attached by some tools);
  5612 
  5613 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  5614 mode and goal output format:
  5615 
  5616 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  5617 244c244
  5618 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  5619 ---
  5620 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  5621 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  5622 181c181
  5623 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  5624 ---
  5625 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  5626 
  5627 * function bind_thms stores lists of theorems (cf. bind_thm);
  5628 
  5629 * new shorthand tactics ftac, eatac, datac, fatac;
  5630 
  5631 * qed (and friends) now accept "" as result name; in that case the
  5632 theorem is not stored, but proper checks and presentation of the
  5633 result still apply;
  5634 
  5635 * theorem database now also indexes constants "Trueprop", "all",
  5636 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  5637 
  5638 
  5639 *** HOL ***
  5640 
  5641 ** HOL arithmetic **
  5642 
  5643 * There are now decision procedures for linear arithmetic over nat and
  5644 int:
  5645 
  5646 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  5647 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  5648 are treated as atomic; subformulae not involving type `nat' or `int'
  5649 are ignored; quantified subformulae are ignored unless they are
  5650 positive universal or negative existential. The tactic has to be
  5651 invoked by hand and can be a little bit slow. In particular, the
  5652 running time is exponential in the number of occurrences of `min' and
  5653 `max', and `-' on `nat'.
  5654 
  5655 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  5656 (negated) (in)equalities among the premises and the conclusion into
  5657 account (i.e. no compound formulae) and does not know about `min' and
  5658 `max', and `-' on `nat'. It is fast and is used automatically by the
  5659 simplifier.
  5660 
  5661 NB: At the moment, these decision procedures do not cope with mixed
  5662 nat/int formulae where the two parts interact, such as `m < n ==>
  5663 int(m) < int(n)'.
  5664 
  5665 * HOL/Numeral provides a generic theory of numerals (encoded
  5666 efficiently as bit strings); setup for types nat/int/real is in place;
  5667 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  5668 int, existing theories and proof scripts may require a few additional
  5669 type constraints;
  5670 
  5671 * integer division and remainder can now be performed on constant
  5672 arguments;
  5673 
  5674 * many properties of integer multiplication, division and remainder
  5675 are now available;
  5676 
  5677 * An interface to the Stanford Validity Checker (SVC) is available through the
  5678 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  5679 are proved automatically.  SVC must be installed separately, and its results
  5680 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  5681 invocation of the underlying oracle).  For SVC see
  5682   http://verify.stanford.edu/SVC
  5683 
  5684 * IsaMakefile: the HOL-Real target now builds an actual image;
  5685 
  5686 
  5687 ** HOL misc **
  5688 
  5689 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  5690 (in Isabelle/Isar) -- by Gertrud Bauer;
  5691 
  5692 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  5693 analysis for assembly languages with subtypes;
  5694 
  5695 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  5696 -- avoids syntactic ambiguities and treats state, transition, and
  5697 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  5698 changed syntax and (many) tactics;
  5699 
  5700 * HOL/inductive: Now also handles more general introduction rules such
  5701   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  5702   theorems are now maintained within the theory (maintained via the
  5703   "mono" attribute);
  5704 
  5705 * HOL/datatype: Now also handles arbitrarily branching datatypes
  5706   (using function types) such as
  5707 
  5708   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  5709 
  5710 * HOL/record: record_simproc (part of the default simpset) takes care
  5711 of selectors applied to updated records; record_split_tac is no longer
  5712 part of the default claset; update_defs may now be removed from the
  5713 simpset in many cases; COMPATIBILITY: old behavior achieved by
  5714 
  5715   claset_ref () := claset() addSWrapper record_split_wrapper;
  5716   Delsimprocs [record_simproc]
  5717 
  5718 * HOL/typedef: fixed type inference for representing set; type
  5719 arguments now have to occur explicitly on the rhs as type constraints;
  5720 
  5721 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  5722 names rather than an ML expression;
  5723 
  5724 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  5725 supplied later.  Program schemes can be defined, such as
  5726     "While B C s = (if B s then While B C (C s) else s)"
  5727 where the well-founded relation can be chosen after B and C have been given.
  5728 
  5729 * HOL/List: the constructors of type list are now Nil and Cons;
  5730 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  5731 course, ML tools referring to List.list.op # etc. have to be adapted;
  5732 
  5733 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  5734 disabled by default; run isabelle with option -m HOL to get back to
  5735 the original Gordon/HOL-style output;
  5736 
  5737 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  5738 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  5739 
  5740 * HOL basic syntax simplified (more orthogonal): all variants of
  5741 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  5742 Eps operator is provided as well: "SOME x. P[x]";
  5743 
  5744 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  5745 
  5746 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  5747 thus available for user theories;
  5748 
  5749 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  5750 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  5751 time;
  5752 
  5753 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  5754 several times and then mp;
  5755 
  5756 
  5757 *** LK ***
  5758 
  5759 * the notation <<...>> is now available as a notation for sequences of
  5760 formulas;
  5761 
  5762 * the simplifier is now installed
  5763 
  5764 * the axiom system has been generalized (thanks to Soren Heilmann)
  5765 
  5766 * the classical reasoner now has a default rule database
  5767 
  5768 
  5769 *** ZF ***
  5770 
  5771 * new primrec section allows primitive recursive functions to be given
  5772 directly (as in HOL) over datatypes and the natural numbers;
  5773 
  5774 * new tactics induct_tac and exhaust_tac for induction (or case
  5775 analysis) over datatypes and the natural numbers;
  5776 
  5777 * the datatype declaration of type T now defines the recursor T_rec;
  5778 
  5779 * simplification automatically does freeness reasoning for datatype
  5780 constructors;
  5781 
  5782 * automatic type-inference, with AddTCs command to insert new
  5783 type-checking rules;
  5784 
  5785 * datatype introduction rules are now added as Safe Introduction rules
  5786 to the claset;
  5787 
  5788 * the syntax "if P then x else y" is now available in addition to
  5789 if(P,x,y);
  5790 
  5791 
  5792 *** Internal programming interfaces ***
  5793 
  5794 * tuned simplifier trace output; new flag debug_simp;
  5795 
  5796 * structures Vartab / Termtab (instances of TableFun) offer efficient
  5797 tables indexed by indexname_ord / term_ord (compatible with aconv);
  5798 
  5799 * AxClass.axclass_tac lost the theory argument;
  5800 
  5801 * tuned current_goals_markers semantics: begin / end goal avoids
  5802 printing empty lines;
  5803 
  5804 * removed prs and prs_fn hook, which was broken because it did not
  5805 include \n in its semantics, forcing writeln to add one
  5806 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  5807 string -> unit if you really want to output text without newline;
  5808 
  5809 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  5810 plain output, interface builders may have to enable 'isabelle_font'
  5811 mode to get Isabelle font glyphs as before;
  5812 
  5813 * refined token_translation interface; INCOMPATIBILITY: output length
  5814 now of type real instead of int;
  5815 
  5816 * theory loader actions may be traced via new ThyInfo.add_hook
  5817 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  5818 your own database of information attached to *whole* theories -- as
  5819 opposed to intra-theory data slots offered via TheoryDataFun;
  5820 
  5821 * proper handling of dangling sort hypotheses (at last!);
  5822 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  5823 extra sort hypotheses that can be witnessed from the type signature;
  5824 the force_strip_shyps flag is gone, any remaining shyps are simply
  5825 left in the theorem (with a warning issued by strip_shyps_warning);
  5826 
  5827 
  5828 
  5829 New in Isabelle98-1 (October 1998)
  5830 ----------------------------------
  5831 
  5832 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  5833 
  5834 * several changes of automated proof tools;
  5835 
  5836 * HOL: major changes to the inductive and datatype packages, including
  5837 some minor incompatibilities of theory syntax;
  5838 
  5839 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  5840 called `inj_on';
  5841 
  5842 * HOL: removed duplicate thms in Arith:
  5843   less_imp_add_less  should be replaced by  trans_less_add1
  5844   le_imp_add_le      should be replaced by  trans_le_add1
  5845 
  5846 * HOL: unary minus is now overloaded (new type constraints may be
  5847 required);
  5848 
  5849 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  5850 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  5851 now taken as an integer constant.
  5852 
  5853 * Pure: ML function 'theory_of' renamed to 'theory';
  5854 
  5855 
  5856 *** Proof tools ***
  5857 
  5858 * Simplifier:
  5859   1. Asm_full_simp_tac is now more aggressive.
  5860      1. It will sometimes reorient premises if that increases their power to
  5861         simplify.
  5862      2. It does no longer proceed strictly from left to right but may also
  5863         rotate premises to achieve further simplification.
  5864      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  5865      old Asm_full_simp_tac in that it does not rotate premises.
  5866   2. The simplifier now knows a little bit about nat-arithmetic.
  5867 
  5868 * Classical reasoner: wrapper mechanism for the classical reasoner now
  5869 allows for selected deletion of wrappers, by introduction of names for
  5870 wrapper functionals.  This implies that addbefore, addSbefore,
  5871 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  5872 and that adding two tactics with the same name overwrites the first
  5873 one (emitting a warning).
  5874   type wrapper = (int -> tactic) -> (int -> tactic)
  5875   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  5876   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  5877   delWrapper, delSWrapper: claset *  string            -> claset
  5878   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  5879 
  5880 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  5881 semantics; addbefore now affects only the unsafe part of step_tac
  5882 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  5883 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  5884 by Force_tac;
  5885 
  5886 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  5887 compWrapper; added safe wrapper (and access functions for it);
  5888 
  5889 * HOL/split_all_tac is now much faster and fails if there is nothing
  5890 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  5891 and the names of the automatically generated variables have changed.
  5892 split_all_tac has moved within claset() from unsafe wrappers to safe
  5893 wrappers, which means that !!-bound variables are split much more
  5894 aggressively, and safe_tac and clarify_tac now split such variables.
  5895 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  5896 Note: the same holds for record_split_tac, which does the job of
  5897 split_all_tac for record fields.
  5898 
  5899 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  5900 permanently to the default simpset using Addsplits just like
  5901 Addsimps. They can be removed via Delsplits just like
  5902 Delsimps. Lower-case versions are also available.
  5903 
  5904 * HOL/Simplifier: The rule split_if is now part of the default
  5905 simpset. This means that the simplifier will eliminate all occurrences
  5906 of if-then-else in the conclusion of a goal. To prevent this, you can
  5907 either remove split_if completely from the default simpset by
  5908 `Delsplits [split_if]' or remove it in a specific call of the
  5909 simplifier using `... delsplits [split_if]'.  You can also add/delete
  5910 other case splitting rules to/from the default simpset: every datatype
  5911 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  5912 t is the name of the datatype).
  5913 
  5914 * Classical reasoner / Simplifier combination: new force_tac (and
  5915 derivatives Force_tac, force) combines rewriting and classical
  5916 reasoning (and whatever other tools) similarly to auto_tac, but is
  5917 aimed to solve the given subgoal completely.
  5918 
  5919 
  5920 *** General ***
  5921 
  5922 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  5923 and `goalw': the theory is no longer needed as an explicit argument -
  5924 the current theory context is used; assumptions are no longer returned
  5925 at the ML-level unless one of them starts with ==> or !!; it is
  5926 recommended to convert to these new commands using isatool fixgoal
  5927 (backup your sources first!);
  5928 
  5929 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  5930 the current theory context, and 'theory' to lookup stored theories;
  5931 
  5932 * new theory section 'locale' for declaring constants, assumptions and
  5933 definitions that have local scope;
  5934 
  5935 * new theory section 'nonterminals' for purely syntactic types;
  5936 
  5937 * new theory section 'setup' for generic ML setup functions
  5938 (e.g. package initialization);
  5939 
  5940 * the distribution now includes Isabelle icons: see
  5941 lib/logo/isabelle-{small,tiny}.xpm;
  5942 
  5943 * isatool install - install binaries with absolute references to
  5944 ISABELLE_HOME/bin;
  5945 
  5946 * isatool logo -- create instances of the Isabelle logo (as EPS);
  5947 
  5948 * print mode 'emacs' reserved for Isamode;
  5949 
  5950 * support multiple print (ast) translations per constant name;
  5951 
  5952 * theorems involving oracles are now printed with a suffixed [!];
  5953 
  5954 
  5955 *** HOL ***
  5956 
  5957 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  5958 
  5959 * HOL/inductive package reorganized and improved: now supports mutual
  5960 definitions such as
  5961 
  5962   inductive EVEN ODD
  5963     intrs
  5964       null "0 : EVEN"
  5965       oddI "n : EVEN ==> Suc n : ODD"
  5966       evenI "n : ODD ==> Suc n : EVEN"
  5967 
  5968 new theorem list "elims" contains an elimination rule for each of the
  5969 recursive sets; inductive definitions now handle disjunctive premises
  5970 correctly (also ZF);
  5971 
  5972 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  5973 "mutual_induct" no longer exists - the induction rule is always
  5974 contained in "induct";
  5975 
  5976 
  5977 * HOL/datatype package re-implemented and greatly improved: now
  5978 supports mutually recursive datatypes such as
  5979 
  5980   datatype
  5981     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  5982             | SUM ('a aexp) ('a aexp)
  5983             | DIFF ('a aexp) ('a aexp)
  5984             | NUM 'a
  5985   and
  5986     'a bexp = LESS ('a aexp) ('a aexp)
  5987             | AND ('a bexp) ('a bexp)
  5988             | OR ('a bexp) ('a bexp)
  5989 
  5990 as well as indirectly recursive datatypes such as
  5991 
  5992   datatype
  5993     ('a, 'b) term = Var 'a
  5994                   | App 'b ((('a, 'b) term) list)
  5995 
  5996 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  5997 induction on mutually / indirectly recursive datatypes.
  5998 
  5999 Primrec equations are now stored in theory and can be accessed via
  6000 <function_name>.simps.
  6001 
  6002 INCOMPATIBILITIES:
  6003 
  6004   - Theories using datatypes must now have theory Datatype as an
  6005     ancestor.
  6006   - The specific <typename>.induct_tac no longer exists - use the
  6007     generic induct_tac instead.
  6008   - natE has been renamed to nat.exhaust - use exhaust_tac
  6009     instead of res_inst_tac ... natE. Note that the variable
  6010     names in nat.exhaust differ from the names in natE, this
  6011     may cause some "fragile" proofs to fail.
  6012   - The theorems split_<typename>_case and split_<typename>_case_asm
  6013     have been renamed to <typename>.split and <typename>.split_asm.
  6014   - Since default sorts of type variables are now handled correctly,
  6015     some datatype definitions may have to be annotated with explicit
  6016     sort constraints.
  6017   - Primrec definitions no longer require function name and type
  6018     of recursive argument.
  6019 
  6020 Consider using isatool fixdatatype to adapt your theories and proof
  6021 scripts to the new package (backup your sources first!).
  6022 
  6023 
  6024 * HOL/record package: considerably improved implementation; now
  6025 includes concrete syntax for record types, terms, updates; theorems
  6026 for surjective pairing and splitting !!-bound record variables; proof
  6027 support is as follows:
  6028 
  6029   1) standard conversions (selectors or updates applied to record
  6030 constructor terms) are part of the standard simpset;
  6031 
  6032   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  6033 made part of standard simpset and claset via addIffs;
  6034 
  6035   3) a tactic for record field splitting (record_split_tac) is part of
  6036 the standard claset (addSWrapper);
  6037 
  6038 To get a better idea about these rules you may retrieve them via
  6039 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  6040 the name of your record type.
  6041 
  6042 The split tactic 3) conceptually simplifies by the following rule:
  6043 
  6044   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  6045 
  6046 Thus any record variable that is bound by meta-all will automatically
  6047 blow up into some record constructor term, consequently the
  6048 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  6049 solve record problems automatically.
  6050 
  6051 
  6052 * reorganized the main HOL image: HOL/Integ and String loaded by
  6053 default; theory Main includes everything;
  6054 
  6055 * automatic simplification of integer sums and comparisons, using cancellation;
  6056 
  6057 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  6058 
  6059 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  6060 
  6061 * many new identities for unions, intersections, set difference, etc.;
  6062 
  6063 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  6064 called split_if, split_split, split_sum_case and split_nat_case (to go
  6065 with add/delsplits);
  6066 
  6067 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  6068 (?x::unit) = (); this is made part of the default simpset, which COULD
  6069 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  6070 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  6071 unit_abs_eta_conv is added in order to counter the effect of
  6072 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  6073 %u.f();
  6074 
  6075 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  6076 makes more sense);
  6077 
  6078 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6079   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6080   disjointness reasoning but breaking a few old proofs.
  6081 
  6082 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  6083 to 'converse' from 'inverse' (for compatibility with ZF and some
  6084 literature);
  6085 
  6086 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  6087 the well-founded relation;
  6088 
  6089 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  6090     Compl A.  The "Compl" syntax remains available as input syntax for this
  6091     release ONLY.
  6092 
  6093 * HOL/Update: new theory of function updates:
  6094     f(a:=b) == %x. if x=a then b else f x
  6095 may also be iterated as in f(a:=b,c:=d,...);
  6096 
  6097 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  6098 
  6099 * HOL/List:
  6100   - new function list_update written xs[i:=v] that updates the i-th
  6101     list position. May also be iterated as in xs[i:=a,j:=b,...].
  6102   - new function `upt' written [i..j(] which generates the list
  6103     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  6104     bound write [i..j], which is a shorthand for [i..j+1(].
  6105   - new lexicographic orderings and corresponding wellfoundedness theorems.
  6106 
  6107 * HOL/Arith:
  6108   - removed 'pred' (predecessor) function;
  6109   - generalized some theorems about n-1;
  6110   - many new laws about "div" and "mod";
  6111   - new laws about greatest common divisors (see theory ex/Primes);
  6112 
  6113 * HOL/Relation: renamed the relational operator r^-1 "converse"
  6114 instead of "inverse";
  6115 
  6116 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  6117   of the multiset ordering;
  6118 
  6119 * directory HOL/Real: a construction of the reals using Dedekind cuts
  6120   (not included by default);
  6121 
  6122 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  6123 
  6124 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  6125   programs, i.e. different program variables may have different types.
  6126 
  6127 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6128   [previously, this check worked only if the rewrite rule was unconditional]
  6129   Now rew can involve either definitions or equalities (either == or =).
  6130 
  6131 
  6132 *** ZF ***
  6133 
  6134 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  6135   only the theorems proved on ZF.ML;
  6136 
  6137 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  6138   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  6139   disjointness reasoning but breaking a few old proofs.
  6140 
  6141 * ZF/Update: new theory of function updates
  6142     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  6143   may also be iterated as in f(a:=b,c:=d,...);
  6144 
  6145 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  6146 
  6147 * calling (stac rew i) now fails if "rew" has no effect on the goal
  6148   [previously, this check worked only if the rewrite rule was unconditional]
  6149   Now rew can involve either definitions or equalities (either == or =).
  6150 
  6151 * case_tac provided for compatibility with HOL
  6152     (like the old excluded_middle_tac, but with subgoals swapped)
  6153 
  6154 
  6155 *** Internal programming interfaces ***
  6156 
  6157 * Pure: several new basic modules made available for general use, see
  6158 also src/Pure/README;
  6159 
  6160 * improved the theory data mechanism to support encapsulation (data
  6161 kind name replaced by private Object.kind, acting as authorization
  6162 key); new type-safe user interface via functor TheoryDataFun; generic
  6163 print_data function becomes basically useless;
  6164 
  6165 * removed global_names compatibility flag -- all theory declarations
  6166 are qualified by default;
  6167 
  6168 * module Pure/Syntax now offers quote / antiquote translation
  6169 functions (useful for Hoare logic etc. with implicit dependencies);
  6170 see HOL/ex/Antiquote for an example use;
  6171 
  6172 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  6173 cterm -> thm;
  6174 
  6175 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  6176 subgoal;
  6177 
  6178 * Display.print_goals function moved to Locale.print_goals;
  6179 
  6180 * standard print function for goals supports current_goals_markers
  6181 variable for marking begin of proof, end of proof, start of goal; the
  6182 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  6183 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  6184 for example;
  6185 
  6186 
  6187 
  6188 New in Isabelle98 (January 1998)
  6189 --------------------------------
  6190 
  6191 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6192 
  6193 * changed lexical syntax of terms / types: dots made part of long
  6194 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  6195 
  6196 * simpset (and claset) reference variable replaced by functions
  6197 simpset / simpset_ref;
  6198 
  6199 * no longer supports theory aliases (via merge) and non-trivial
  6200 implicit merge of thms' signatures;
  6201 
  6202 * most internal names of constants changed due to qualified names;
  6203 
  6204 * changed Pure/Sequence interface (see Pure/seq.ML);
  6205 
  6206 
  6207 *** General Changes ***
  6208 
  6209 * hierachically structured name spaces (for consts, types, axms, thms
  6210 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  6211 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  6212 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  6213 long_names for fully qualified output names; NOTE: ML programs
  6214 (special tactics, packages etc.) referring to internal names may have
  6215 to be adapted to cope with fully qualified names; in case of severe
  6216 backward campatibility problems try setting 'global_names' at compile
  6217 time to have enrything declared within a flat name space; one may also
  6218 fine tune name declarations in theories via the 'global' and 'local'
  6219 section;
  6220 
  6221 * reimplemented the implicit simpset and claset using the new anytype
  6222 data filed in signatures; references simpset:simpset ref etc. are
  6223 replaced by functions simpset:unit->simpset and
  6224 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  6225 to patch your ML files accordingly;
  6226 
  6227 * HTML output now includes theory graph data for display with Java
  6228 applet or isatool browser; data generated automatically via isatool
  6229 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  6230 
  6231 * defs may now be conditional; improved rewrite_goals_tac to handle
  6232 conditional equations;
  6233 
  6234 * defs now admits additional type arguments, using TYPE('a) syntax;
  6235 
  6236 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  6237 creates a new theory node; implicit merge of thms' signatures is
  6238 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  6239 transfer:theory->thm->thm in (rare) cases;
  6240 
  6241 * improved handling of draft signatures / theories; draft thms (and
  6242 ctyps, cterms) are automatically promoted to real ones;
  6243 
  6244