NEWS

replace some continuous_on lemmas with more general versions

Isabelle NEWS -- history user-relevant changes
==============================================

New in this Isabelle version
----------------------------

*** General ***

* Theory loader: source files are identified by content via SHA1
digests.  Discontinued former path/modtime identification and optional
ISABELLE_FILE_IDENT plugin scripts.

* Parallelization of nested Isar proofs is subject to
Goal.parallel_proofs_threshold (default 100).  See also isabelle
usedir option -Q.

* Discontinued support for Poly/ML 5.2, which was the last version
without proper multithreading and TimeLimit implementation.

* Discontinued old lib/scripts/polyml-platform, which has been
obsolete since Isabelle2009-2.

* Theory loader: source files are exclusively located via the master
directory of each theory node (where the .thy file itself resides).
The global load path (such as src/HOL/Library) has been discontinued.
Note that the path element ~~ may be used to reference theories in the
Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
INCOMPATIBILITY.

* Various optional external tools are referenced more robustly and
uniformly by explicit Isabelle settings as follows:

  ISABELLE_CSDP   (formerly CSDP_EXE)
  ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
  ISABELLE_OCAML  (formerly EXEC_OCAML)
  ISABELLE_SWIPL  (formerly EXEC_SWIPL)
  ISABELLE_YAP    (formerly EXEC_YAP)

Note that automated detection from the file-system or search path has
been discontinued.  INCOMPATIBILITY.

* Name space: former unsynchronized references are now proper
configuration options, with more conventional names:

  long_names   ~> names_long
  short_names  ~> names_short
  unique_names ~> names_unique

Minor INCOMPATIBILITY, need to declare options in context like this:

  declare [[names_unique = false]]

* Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
that the result needs to be unique, which means fact specifications
may have to be refined after enriching a proof context.

* Isabelle/Isar reference manual provides more formal references in
syntax diagrams.

* Attribute case_names has been refined: the assumptions in each case can
be named now by following the case name with [name1 name2 ...].


*** HOL ***

* Classes bot and top require underlying partial order rather than preorder:
uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.

* Class complete_lattice: generalized a couple of lemmas from sets;
generalized theorems INF_cong and SUP_cong.  New type classes for complete
boolean algebras and complete linear orders.  Lemmas Inf_less_iff,
less_Sup_iff, INF_less_iff, less_SUP_iff now reside in class complete_linorder.
Changed proposition of lemmas Inf_bool_def, Sup_bool_def, Inf_fun_def, Sup_fun_def,
Inf_apply, Sup_apply.
Redundant lemmas Inf_singleton, Sup_singleton, Inf_binary, Sup_binary,
INF_eq, SUP_eq, INF_UNIV_range, SUP_UNIV_range, Int_eq_Inter,
INTER_eq_Inter_image, Inter_def, INT_eq, Un_eq_Union, UNION_eq_Union_image,
Union_def, UN_singleton, UN_eq have been discarded.
More consistent and less misunderstandable names:
  INFI_def ~> INF_def
  SUPR_def ~> SUP_def
  INF_leI ~> INF_lower
  INF_leI2 ~> INF_lower2
  le_INFI ~> INF_greatest
  le_SUPI ~> SUP_upper
  le_SUPI2 ~> SUP_upper2
  SUP_leI ~> SUP_least
  INFI_bool_eq ~> INF_bool_eq
  SUPR_bool_eq ~> SUP_bool_eq
  INFI_apply ~> INF_apply
  SUPR_apply ~> SUP_apply
  INTER_def ~> INTER_eq
  UNION_def ~> UNION_eq

INCOMPATIBILITY.

* Theorem collections ball_simps and bex_simps do not contain theorems referring
to UNION any longer;  these have been moved to collection UN_ball_bex_simps.
INCOMPATIBILITY.

* Archimedean_Field.thy:
    floor now is defined as parameter of a separate type class floor_ceiling.
 
* Finite_Set.thy: more coherent development of fold_set locales:

    locale fun_left_comm ~> locale comp_fun_commute
    locale fun_left_comm_idem ~> locale comp_fun_idem
    
Both use point-free characterisation; interpretation proofs may need adjustment.
INCOMPATIBILITY.

* Code generation:
  - theory Library/Code_Char_ord provides native ordering of characters
    in the target language.
  - commands code_module and code_library are legacy, use export_code instead. 
  - method evaluation is legacy, use method eval instead.
  - legacy evaluator "SML" is deactivated by default. To activate it, add the following
    line in your theory:
      setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
 
* Declare ext [intro] by default.  Rare INCOMPATIBILITY.

* Nitpick:
  - Added "need" and "total_consts" options.
  - Reintroduced "show_skolems" option by popular demand.
  - Renamed attribute: nitpick_def ~> nitpick_unfold.
    INCOMPATIBILITY.

* Sledgehammer:
  - sledgehammer available_provers ~> sledgehammer supported_provers.
    INCOMPATIBILITY.
  - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    TPTP problems (TFF).
  - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
    and "max_new_mono_instances" options.
  - Removed "explicit_apply" and "full_types" options as well as "Full Types"
    Proof General menu item. INCOMPATIBILITY.

* Metis:
  - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
  - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.

* "try":
  - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
    options. INCOMPATIBILITY.
  - Introduced "try" that not only runs "try_methods" but also "solve_direct",
    "sledgehammer", "quickcheck", and "nitpick".

* Quickcheck:
  - Added "eval" option to evaluate terms for the found counterexample
    (currently only supported by the default (exhaustive) tester)
  - Added post-processing of terms to obtain readable counterexamples
    (currently only supported by the default (exhaustive) tester)
  - New counterexample generator quickcheck[narrowing] enables
    narrowing-based testing.
    It requires that the Glasgow Haskell compiler is installed and
    its location is known to Isabelle with the environment variable
    ISABELLE_GHC.
  - Removed quickcheck tester "SML" based on the SML code generator
    from HOL-Library

* Function package: discontinued option "tailrec".
INCOMPATIBILITY. Use partial_function instead.

* HOL-Probability:
  - Caratheodory's extension lemma is now proved for ring_of_sets.
  - Infinite products of probability measures are now available.
  - Use extended reals instead of positive extended reals.
    INCOMPATIBILITY.

* Old recdef package has been moved to Library/Old_Recdef.thy, where it
must be loaded explicitly.  INCOMPATIBILITY.

* Well-founded recursion combinator "wfrec" has been moved to
Library/Wfrec.thy. INCOMPATIBILITY.

* Theory Library/Nat_Infinity has been renamed to Library/Extended_Nat.
The names of the following types and constants have changed:
  inat (type) ~> enat
  Fin         ~> enat
  Infty       ~> infinity (overloaded)
  iSuc        ~> eSuc
  the_Fin     ~> the_enat
Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
been renamed accordingly.

* Limits.thy: Type "'a net" has been renamed to "'a filter", in
accordance with standard mathematical terminology. INCOMPATIBILITY.

* Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
"Cart_nth" and "Cart_lambda" have been respectively renamed to
"vec_nth" and "vec_lambda"; theorems mentioning those names have
changed to match. Definition theorems for overloaded constants now use
the standard "foo_vec_def" naming scheme. A few other theorems have
been renamed as follows (INCOMPATIBILITY):

  Cart_eq          ~> vec_eq_iff
  dist_nth_le_cart ~> dist_vec_nth_le
  tendsto_vector   ~> vec_tendstoI
  Cauchy_vector    ~> vec_CauchyI

* Session Multivariate_Analysis: Several duplicate theorems have been
removed, and other theorems have been renamed. INCOMPATIBILITY.

  eventually_conjI ~> eventually_conj
  eventually_and ~> eventually_conj_iff
  eventually_false ~> eventually_False
  Lim_ident_at ~> LIM_ident
  Lim_const ~> tendsto_const
  Lim_cmul ~> tendsto_scaleR [OF tendsto_const]
  Lim_neg ~> tendsto_minus
  Lim_add ~> tendsto_add
  Lim_sub ~> tendsto_diff
  Lim_mul ~> tendsto_scaleR
  Lim_vmul ~> tendsto_scaleR [OF _ tendsto_const]
  Lim_null_norm ~> tendsto_norm_zero_iff [symmetric]
  Lim_linear ~> bounded_linear.tendsto
  Lim_component ~> tendsto_euclidean_component
  Lim_component_cart ~> tendsto_vec_nth
  Lim_inner ~> tendsto_inner [OF tendsto_const]
  dot_lsum ~> inner_setsum_left
  dot_rsum ~> inner_setsum_right
  continuous_on_neg ~> continuous_on_minus
  continuous_on_sub ~> continuous_on_diff
  continuous_on_cmul ~> continuous_on_scaleR [OF continuous_on_const]
  continuous_on_vmul ~> continuous_on_scaleR [OF _ continuous_on_const]
  continuous_on_mul ~> continuous_on_scaleR
  continuous_on_mul_real ~> continuous_on_mult
  continuous_on_inner ~> continuous_on_inner [OF continuous_on_const]
  subset_interior ~> interior_mono
  subset_closure ~> closure_mono
  closure_univ ~> closure_UNIV

* Complex_Main: The locale interpretations for the bounded_linear and
bounded_bilinear locales have been removed, in order to reduce the
number of duplicate lemmas. Users must use the original names for
distributivity theorems, potential INCOMPATIBILITY.

  divide.add ~> add_divide_distrib
  divide.diff ~> diff_divide_distrib
  divide.setsum ~> setsum_divide_distrib
  mult.add_right ~> right_distrib
  mult.diff_right ~> right_diff_distrib
  mult_right.setsum ~> setsum_right_distrib
  mult_left.diff ~> left_diff_distrib

* Complex_Main: Several redundant theorems about real numbers have
been removed or generalized and renamed. INCOMPATIBILITY.

  real_0_le_divide_iff ~> zero_le_divide_iff
  realpow_two_disj ~> power2_eq_iff
  real_squared_diff_one_factored ~> square_diff_one_factored
  realpow_two_diff ~> square_diff_square_factored
  exp_ln_eq ~> ln_unique
  lemma_DERIV_subst ~> DERIV_cong


*** Document preparation ***

* Discontinued special treatment of hard tabulators, which are better
avoided in the first place.  Implicit tab-width is 1.

* Antiquotation @{rail} layouts railroad syntax diagrams, see also
isar-ref manual.

* Antiquotation @{value} evaluates the given term and presents its result.

* Localized \isabellestyle switch can be used within blocks or groups
like this:

  \isabellestyle{it}  %preferred default
  {\isabellestylett @{text "typewriter stuff"}}

* New term style "isub" as ad-hoc conversion of variables x1, y23 into
subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.

* Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
(e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).


*** ML ***

* The inner syntax of sort/type/term/prop supports inlined YXML
representations within quoted string tokens.  By encoding logical
entities via Term_XML (in ML or Scala) concrete syntax can be
bypassed, which is particularly useful for producing bits of text
under external program control.

* Antiquotations for ML and document preparation are managed as theory
data, which requires explicit setup.

* Isabelle_Process.is_active allows tools to check if the official
process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
(better known as Proof General).

* Structure Proof_Context follows standard naming scheme.  Old
ProofContext is still available for some time as legacy alias.

* Structure Timing provides various operations for timing; supersedes
former start_timing/end_timing etc.

* Path.print is the official way to show file-system paths to users
(including quotes etc.).

* Inner syntax: identifiers in parse trees of generic categories
"logic", "aprop", "idt" etc. carry position information (disguised as
type constraints).  Occasional INCOMPATIBILITY with non-compliant
translations that choke on unexpected type constraints.  Positions can
be stripped in ML translations via Syntax.strip_positions /
Syntax.strip_positions_ast, or via the syntax constant
"_strip_positions" within parse trees.  As last resort, positions can
be disabled via the configuration option Syntax.positions, which is
called "syntax_positions" in Isar attribute syntax.

* Discontinued special status of various ML structures that contribute
to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
refer directly to Ast.Constant, Lexicon.is_identifier,
Syntax_Trans.mk_binder_tr etc.

* Typed print translation: discontinued show_sorts argument, which is
already available via context of "advanced" translation.

* Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
goal states; body tactic needs to address all subgoals uniformly.

* Slightly more special eq_list/eq_set, with shortcut involving
pointer equality (assumes that eq relation is reflexive).

* Classical tactics use proper Proof.context instead of historic types
claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
operate directly on Proof.context.  Raw type claset retains its use as
snapshot of the classical context, which can be recovered via
(put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
INCOMPATIBILITY, classical tactics and derived proof methods require
proper Proof.context.

* Scala layer provides JVM method invocation service for static
methods of type (String)String, see Invoke_Scala.method in ML.
For example:

  Invoke_Scala.method "java.lang.System.getProperty" "java.home"



New in Isabelle2011 (January 2011)
----------------------------------

*** General ***

* Experimental Prover IDE based on Isabelle/Scala and jEdit (see
src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
useful tooltips and hyperlinks produced from its static analysis.  The
bundled component provides an executable Isabelle tool that can be run
like this:

  Isabelle2011/bin/isabelle jedit

* Significantly improved Isabelle/Isar implementation manual.

* System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
(and thus refers to something like $HOME/.isabelle/Isabelle2011),
while the default heap location within that directory lacks that extra
suffix.  This isolates multiple Isabelle installations from each
other, avoiding problems with old settings in new versions.
INCOMPATIBILITY, need to copy/upgrade old user settings manually.

* Source files are always encoded as UTF-8, instead of old-fashioned
ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
the following package declarations:

  \usepackage[utf8]{inputenc}
  \usepackage{textcomp}

* Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
a Unicode character is treated as a single symbol, not a sequence of
non-ASCII bytes as before.  Since Isabelle/ML string literals may
contain symbols without further backslash escapes, Unicode can now be
used here as well.  Recall that Symbol.explode in ML provides a
consistent view on symbols, while raw explode (or String.explode)
merely give a byte-oriented representation.

* Theory loader: source files are primarily located via the master
directory of each theory node (where the .thy file itself resides).
The global load path is still partially available as legacy feature.
Minor INCOMPATIBILITY due to subtle change in file lookup: use
explicit paths, relatively to the theory.

* Special treatment of ML file names has been discontinued.
Historically, optional extensions .ML or .sml were added on demand --
at the cost of clarity of file dependencies.  Recall that Isabelle/ML
files exclusively use the .ML extension.  Minor INCOMPATIBILTY.

* Various options that affect pretty printing etc. are now properly
handled within the context via configuration options, instead of
unsynchronized references or print modes.  There are both ML Config.T
entities and Isar declaration attributes to access these.

  ML (Config.T)                 Isar (attribute)

  eta_contract                  eta_contract
  show_brackets                 show_brackets
  show_sorts                    show_sorts
  show_types                    show_types
  show_question_marks           show_question_marks
  show_consts                   show_consts
  show_abbrevs                  show_abbrevs

  Syntax.ast_trace              syntax_ast_trace
  Syntax.ast_stat               syntax_ast_stat
  Syntax.ambiguity_level        syntax_ambiguity_level

  Goal_Display.goals_limit      goals_limit
  Goal_Display.show_main_goal   show_main_goal

  Method.rule_trace             rule_trace

  Thy_Output.display            thy_output_display
  Thy_Output.quotes             thy_output_quotes
  Thy_Output.indent             thy_output_indent
  Thy_Output.source             thy_output_source
  Thy_Output.break              thy_output_break

Note that corresponding "..._default" references in ML may only be
changed globally at the ROOT session setup, but *not* within a theory.
The option "show_abbrevs" supersedes the former print mode
"no_abbrevs" with inverted meaning.

* More systematic naming of some configuration options.
INCOMPATIBILITY.

  trace_simp  ~>  simp_trace
  debug_simp  ~>  simp_debug

* Support for real valued configuration options, using simplistic
floating-point notation that coincides with the inner syntax for
float_token.

* Support for real valued preferences (with approximative PGIP type):
front-ends need to accept "pgint" values in float notation.
INCOMPATIBILITY.

* The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
DejaVu Sans.

* Discontinued support for Poly/ML 5.0 and 5.1 versions.


*** Pure ***

* Command 'type_synonym' (with single argument) replaces somewhat
outdated 'types', which is still available as legacy feature for some
time.

* Command 'nonterminal' (with 'and' separated list of arguments)
replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.

* Command 'notepad' replaces former 'example_proof' for
experimentation in Isar without any result.  INCOMPATIBILITY.

* Locale interpretation commands 'interpret' and 'sublocale' accept
lists of equations to map definitions in a locale to appropriate
entities in the context of the interpretation.  The 'interpretation'
command already provided this functionality.

* Diagnostic command 'print_dependencies' prints the locale instances
that would be activated if the specified expression was interpreted in
the current context.  Variant "print_dependencies!" assumes a context
without interpretations.

* Diagnostic command 'print_interps' prints interpretations in proofs
in addition to interpretations in theories.

* Discontinued obsolete 'global' and 'local' commands to manipulate
the theory name space.  Rare INCOMPATIBILITY.  The ML functions
Sign.root_path and Sign.local_path may be applied directly where this
feature is still required for historical reasons.

* Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
'definition' instead.

* The "prems" fact, which refers to the accidental collection of
foundational premises in the context, is now explicitly marked as
legacy feature and will be discontinued soon.  Consider using "assms"
of the head statement or reference facts by explicit names.

* Document antiquotations @{class} and @{type} print classes and type
constructors.

* Document antiquotation @{file} checks file/directory entries within
the local file system.


*** HOL ***

* Coercive subtyping: functions can be declared as coercions and type
inference will add them as necessary upon input of a term.  Theory
Complex_Main declares real :: nat => real and real :: int => real as
coercions. A coercion function f is declared like this:

  declare [[coercion f]]

To lift coercions through type constructors (e.g. from nat => real to
nat list => real list), map functions can be declared, e.g.

  declare [[coercion_map map]]

Currently coercion inference is activated only in theories including
real numbers, i.e. descendants of Complex_Main.  This is controlled by
the configuration option "coercion_enabled", e.g. it can be enabled in
other theories like this:

  declare [[coercion_enabled]]

* Command 'partial_function' provides basic support for recursive
function definitions over complete partial orders.  Concrete instances
are provided for i) the option type, ii) tail recursion on arbitrary
types, and iii) the heap monad of Imperative_HOL.  See
src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
for examples.

* Function package: f.psimps rules are no longer implicitly declared
as [simp].  INCOMPATIBILITY.

* Datatype package: theorems generated for executable equality (class
"eq") carry proper names and are treated as default code equations.

* Inductive package: now offers command 'inductive_simps' to
automatically derive instantiated and simplified equations for
inductive predicates, similar to 'inductive_cases'.

* Command 'enriched_type' allows to register properties of the
functorial structure of types.

* Improved infrastructure for term evaluation using code generator
techniques, in particular static evaluation conversions.

* Code generator: Scala (2.8 or higher) has been added to the target
languages.

* Code generator: globbing constant expressions "*" and "Theory.*"
have been replaced by the more idiomatic "_" and "Theory._".
INCOMPATIBILITY.

* Code generator: export_code without explicit file declaration prints
to standard output.  INCOMPATIBILITY.

* Code generator: do not print function definitions for case
combinators any longer.

* Code generator: simplification with rules determined with
src/Tools/Code/code_simp.ML and method "code_simp".

* Code generator for records: more idiomatic representation of record
types.  Warning: records are not covered by ancient SML code
generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
rep_datatype declaration helps to succeed then:

  record 'a foo = ...
  ...
  rep_datatype foo_ext ...

* Records: logical foundation type for records does not carry a
'_type' suffix any longer (obsolete due to authentic syntax).
INCOMPATIBILITY.

* Quickcheck now by default uses exhaustive testing instead of random
testing.  Random testing can be invoked by "quickcheck [random]",
exhaustive testing by "quickcheck [exhaustive]".

* Quickcheck instantiates polymorphic types with small finite
datatypes by default. This enables a simple execution mechanism to
handle quantifiers and function equality over the finite datatypes.

* Quickcheck random generator has been renamed from "code" to
"random".  INCOMPATIBILITY.

* Quickcheck now has a configurable time limit which is set to 30
seconds by default. This can be changed by adding [timeout = n] to the
quickcheck command. The time limit for Auto Quickcheck is still set
independently.

* Quickcheck in locales considers interpretations of that locale for
counter example search.

* Sledgehammer:
  - Added "smt" and "remote_smt" provers based on the "smt" proof
    method. See the Sledgehammer manual for details ("isabelle doc
    sledgehammer").
  - Renamed commands:
    sledgehammer atp_info ~> sledgehammer running_provers
    sledgehammer atp_kill ~> sledgehammer kill_provers
    sledgehammer available_atps ~> sledgehammer available_provers
    INCOMPATIBILITY.
  - Renamed options:
    sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
    sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
    sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
    (and "ms" and "min" are no longer supported)
    INCOMPATIBILITY.

* Nitpick:
  - Renamed options:
    nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
    nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
    INCOMPATIBILITY.
  - Added support for partial quotient types.
  - Added local versions of the "Nitpick.register_xxx" functions.
  - Added "whack" option.
  - Allow registration of quotient types as codatatypes.
  - Improved "merge_type_vars" option to merge more types.
  - Removed unsound "fast_descrs" option.
  - Added custom symmetry breaking for datatypes, making it possible to reach
    higher cardinalities.
  - Prevent the expansion of too large definitions.

* Proof methods "metis" and "meson" now have configuration options
"meson_trace", "metis_trace", and "metis_verbose" that can be enabled
to diagnose these tools. E.g.

    using [[metis_trace = true]]

* Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
manually as command 'solve_direct'.

* The default SMT solver Z3 must be enabled explicitly (due to
licensing issues) by setting the environment variable
Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
commercial applications, the SMT solver CVC3 is provided as fall-back;
changing the SMT solver is done via the configuration option
"smt_solver".

* Remote SMT solvers need to be referred to by the "remote_" prefix,
i.e. "remote_cvc3" and "remote_z3".

* Added basic SMT support for datatypes, records, and typedefs using
the oracle mode (no proofs).  Direct support of pairs has been dropped
in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
support for a similar behavior).  Minor INCOMPATIBILITY.

* Changed SMT configuration options:
  - Renamed:
    z3_proofs ~> smt_oracle (with inverted meaning)
    z3_trace_assms ~> smt_trace_used_facts
    INCOMPATIBILITY.
  - Added:
    smt_verbose
    smt_random_seed
    smt_datatypes
    smt_infer_triggers
    smt_monomorph_limit
    cvc3_options
    remote_cvc3_options
    remote_z3_options
    yices_options

* Boogie output files (.b2i files) need to be declared in the theory
header.

* Simplification procedure "list_to_set_comprehension" rewrites list
comprehensions applied to List.set to set comprehensions.  Occasional
INCOMPATIBILITY, may be deactivated like this:

  declare [[simproc del: list_to_set_comprehension]]

* Removed old version of primrec package.  INCOMPATIBILITY.

* Removed simplifier congruence rule of "prod_case", as has for long
been the case with "split".  INCOMPATIBILITY.

* String.literal is a type, but not a datatype.  INCOMPATIBILITY.

* Removed [split_format ... and ... and ...] version of
[split_format].  Potential INCOMPATIBILITY.

* Predicate "sorted" now defined inductively, with nice induction
rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.

* Constant "contents" renamed to "the_elem", to free the generic name
contents for other uses.  INCOMPATIBILITY.

* Renamed class eq and constant eq (for code generation) to class
equal and constant equal, plus renaming of related facts and various
tuning.  INCOMPATIBILITY.

* Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.

* Removed output syntax "'a ~=> 'b" for "'a => 'b option".
INCOMPATIBILITY.

* Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
avoid confusion with finite sets.  INCOMPATIBILITY.

* Abandoned locales equiv, congruent and congruent2 for equivalence
relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
for congruent(2)).

* Some previously unqualified names have been qualified:

  types
    bool ~> HOL.bool
    nat ~> Nat.nat

  constants
    Trueprop ~> HOL.Trueprop
    True ~> HOL.True
    False ~> HOL.False
    op & ~> HOL.conj
    op | ~> HOL.disj
    op --> ~> HOL.implies
    op = ~> HOL.eq
    Not ~> HOL.Not
    The ~> HOL.The
    All ~> HOL.All
    Ex ~> HOL.Ex
    Ex1 ~> HOL.Ex1
    Let ~> HOL.Let
    If ~> HOL.If
    Ball ~> Set.Ball
    Bex ~> Set.Bex
    Suc ~> Nat.Suc
    Pair ~> Product_Type.Pair
    fst ~> Product_Type.fst
    snd ~> Product_Type.snd
    curry ~> Product_Type.curry
    op : ~> Set.member
    Collect ~> Set.Collect

INCOMPATIBILITY.

* More canonical naming convention for some fundamental definitions:

    bot_bool_eq ~> bot_bool_def
    top_bool_eq ~> top_bool_def
    inf_bool_eq ~> inf_bool_def
    sup_bool_eq ~> sup_bool_def
    bot_fun_eq  ~> bot_fun_def
    top_fun_eq  ~> top_fun_def
    inf_fun_eq  ~> inf_fun_def
    sup_fun_eq  ~> sup_fun_def

INCOMPATIBILITY.

* More stylized fact names:

  expand_fun_eq ~> fun_eq_iff
  expand_set_eq ~> set_eq_iff
  set_ext       ~> set_eqI
  nat_number    ~> eval_nat_numeral

INCOMPATIBILITY.

* Refactoring of code-generation specific operations in theory List:

  constants
    null ~> List.null

  facts
    mem_iff ~> member_def
    null_empty ~> null_def

INCOMPATIBILITY.  Note that these were not supposed to be used
regularly unless for striking reasons; their main purpose was code
generation.

Various operations from the Haskell prelude are used for generating
Haskell code.

* Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
"surj f" is now an abbreviation of "range f = UNIV".  The theorems
bij_def and surj_def are unchanged.  INCOMPATIBILITY.

* Abolished some non-alphabetic type names: "prod" and "sum" replace
"*" and "+" respectively.  INCOMPATIBILITY.

* Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
"Sum_Type.Plus" instead.

* Constant "split" has been merged with constant "prod_case"; names of
ML functions, facts etc. involving split have been retained so far,
though.  INCOMPATIBILITY.

* Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
instead.  INCOMPATIBILITY.

* Removed lemma "Option.is_none_none" which duplicates "is_none_def".
INCOMPATIBILITY.

* Former theory Library/Enum is now part of the HOL-Main image.
INCOMPATIBILITY: all constants of the Enum theory now have to be
referred to by its qualified name.

  enum    ~>  Enum.enum
  nlists  ~>  Enum.nlists
  product ~>  Enum.product

* Theory Library/Monad_Syntax provides do-syntax for monad types.
Syntax in Library/State_Monad has been changed to avoid ambiguities.
INCOMPATIBILITY.

* Theory Library/SetsAndFunctions has been split into
Library/Function_Algebras and Library/Set_Algebras; canonical names
for instance definitions for functions; various improvements.
INCOMPATIBILITY.

* Theory Library/Multiset provides stable quicksort implementation of
sort_key.

* Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
INCOMPATIBILITY.

* Session Multivariate_Analysis: introduced a type class for euclidean
space.  Most theorems are now stated in terms of euclidean spaces
instead of finite cartesian products.

  types
    real ^ 'n ~>  'a::real_vector
              ~>  'a::euclidean_space
              ~>  'a::ordered_euclidean_space
        (depends on your needs)

  constants
     _ $ _        ~> _ $$ _
     \<chi> x. _  ~> \<chi>\<chi> x. _
     CARD('n)     ~> DIM('a)

Also note that the indices are now natural numbers and not from some
finite type. Finite cartesian products of euclidean spaces, products
of euclidean spaces the real and complex numbers are instantiated to
be euclidean_spaces.  INCOMPATIBILITY.

* Session Probability: introduced pextreal as positive extended real
numbers.  Use pextreal as value for measures.  Introduce the
Radon-Nikodym derivative, product spaces and Fubini's theorem for
arbitrary sigma finite measures.  Introduces Lebesgue measure based on
the integral in Multivariate Analysis.  INCOMPATIBILITY.

* Session Imperative_HOL: revamped, corrected dozens of inadequacies.
INCOMPATIBILITY.

* Session SPARK (with image HOL-SPARK) provides commands to load and
prove verification conditions generated by the SPARK Ada program
verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.


*** HOL-Algebra ***

* Theorems for additive ring operations (locale abelian_monoid and
descendants) are generated by interpretation from their multiplicative
counterparts.  Names (in particular theorem names) have the mandatory
qualifier 'add'.  Previous theorem names are redeclared for
compatibility.

* Structure "int_ring" is now an abbreviation (previously a
definition).  This fits more natural with advanced interpretations.


*** HOLCF ***

* The domain package now runs in definitional mode by default: The
former command 'new_domain' is now called 'domain'.  To use the domain
package in its original axiomatic mode, use 'domain (unsafe)'.
INCOMPATIBILITY.

* The new class "domain" is now the default sort.  Class "predomain"
is an unpointed version of "domain". Theories can be updated by
replacing sort annotations as shown below.  INCOMPATIBILITY.

  'a::type ~> 'a::countable
  'a::cpo  ~> 'a::predomain
  'a::pcpo ~> 'a::domain

* The old type class "rep" has been superseded by class "domain".
Accordingly, users of the definitional package must remove any
"default_sort rep" declarations.  INCOMPATIBILITY.

* The domain package (definitional mode) now supports unpointed
predomain argument types, as long as they are marked 'lazy'. (Strict
arguments must be in class "domain".) For example, the following
domain definition now works:

  domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")

* Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
instances for types from main HOL: bool, nat, int, char, 'a + 'b,
'a option, and 'a list.  Additionally, it configures fixrec and the
domain package to work with these types.  For example:

  fixrec isInl :: "('a + 'b) u -> tr"
    where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"

  domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")

* The "(permissive)" option of fixrec has been replaced with a
per-equation "(unchecked)" option. See
src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.

* The "bifinite" class no longer fixes a constant "approx"; the class
now just asserts that such a function exists.  INCOMPATIBILITY.

* Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
defines an embedding of type 'a defl into udom by default; instances
of "bifinite" and "domain" classes are available in
src/HOL/HOLCF/Library/Defl_Bifinite.thy.

* The syntax "REP('a)" has been replaced with "DEFL('a)".

* The predicate "directed" has been removed.  INCOMPATIBILITY.

* The type class "finite_po" has been removed.  INCOMPATIBILITY.

* The function "cprod_map" has been renamed to "prod_map".
INCOMPATIBILITY.

* The monadic bind operator on each powerdomain has new binder syntax
similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
"upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".

* The infix syntax for binary union on each powerdomain has changed
from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
syntax.  INCOMPATIBILITY.

* The constant "UU" has been renamed to "bottom".  The syntax "UU" is
still supported as an input translation.

* Renamed some theorems (the original names are also still available).

  expand_fun_below   ~> fun_below_iff
  below_fun_ext      ~> fun_belowI
  expand_cfun_eq     ~> cfun_eq_iff
  ext_cfun           ~> cfun_eqI
  expand_cfun_below  ~> cfun_below_iff
  below_cfun_ext     ~> cfun_belowI
  cont2cont_Rep_CFun ~> cont2cont_APP

* The Abs and Rep functions for various types have changed names.
Related theorem names have also changed to match. INCOMPATIBILITY.

  Rep_CFun  ~> Rep_cfun
  Abs_CFun  ~> Abs_cfun
  Rep_Sprod ~> Rep_sprod
  Abs_Sprod ~> Abs_sprod
  Rep_Ssum  ~> Rep_ssum
  Abs_Ssum  ~> Abs_ssum

* Lemmas with names of the form *_defined_iff or *_strict_iff have
been renamed to *_bottom_iff.  INCOMPATIBILITY.

* Various changes to bisimulation/coinduction with domain package:

  - Definitions of "bisim" constants no longer mention definedness.
  - With mutual recursion, "bisim" predicate is now curried.
  - With mutual recursion, each type gets a separate coind theorem.
  - Variable names in bisim_def and coinduct rules have changed.

INCOMPATIBILITY.

* Case combinators generated by the domain package for type "foo" are
now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.

* Several theorems have been renamed to more accurately reflect the
names of constants and types involved.  INCOMPATIBILITY.

  thelub_const    ~> lub_const
  lub_const       ~> is_lub_const
  thelubI         ~> lub_eqI
  is_lub_lub      ~> is_lubD2
  lubI            ~> is_lub_lub
  unique_lub      ~> is_lub_unique
  is_ub_lub       ~> is_lub_rangeD1
  lub_bin_chain   ~> is_lub_bin_chain
  lub_fun         ~> is_lub_fun
  thelub_fun      ~> lub_fun
  thelub_cfun     ~> lub_cfun
  thelub_Pair     ~> lub_Pair
  lub_cprod       ~> is_lub_prod
  thelub_cprod    ~> lub_prod
  minimal_cprod   ~> minimal_prod
  inst_cprod_pcpo ~> inst_prod_pcpo
  UU_I            ~> bottomI
  compact_UU      ~> compact_bottom
  deflation_UU    ~> deflation_bottom
  finite_deflation_UU ~> finite_deflation_bottom

* Many legacy theorem names have been discontinued.  INCOMPATIBILITY.

  sq_ord_less_eq_trans ~> below_eq_trans
  sq_ord_eq_less_trans ~> eq_below_trans
  refl_less            ~> below_refl
  trans_less           ~> below_trans
  antisym_less         ~> below_antisym
  antisym_less_inverse ~> po_eq_conv [THEN iffD1]
  box_less             ~> box_below
  rev_trans_less       ~> rev_below_trans
  not_less2not_eq      ~> not_below2not_eq
  less_UU_iff          ~> below_UU_iff
  flat_less_iff        ~> flat_below_iff
  adm_less             ~> adm_below
  adm_not_less         ~> adm_not_below
  adm_compact_not_less ~> adm_compact_not_below
  less_fun_def         ~> below_fun_def
  expand_fun_less      ~> fun_below_iff
  less_fun_ext         ~> fun_belowI
  less_discr_def       ~> below_discr_def
  discr_less_eq        ~> discr_below_eq
  less_unit_def        ~> below_unit_def
  less_cprod_def       ~> below_prod_def
  prod_lessI           ~> prod_belowI
  Pair_less_iff        ~> Pair_below_iff
  fst_less_iff         ~> fst_below_iff
  snd_less_iff         ~> snd_below_iff
  expand_cfun_less     ~> cfun_below_iff
  less_cfun_ext        ~> cfun_belowI
  injection_less       ~> injection_below
  less_up_def          ~> below_up_def
  not_Iup_less         ~> not_Iup_below
  Iup_less             ~> Iup_below
  up_less              ~> up_below
  Def_inject_less_eq   ~> Def_below_Def
  Def_less_is_eq       ~> Def_below_iff
  spair_less_iff       ~> spair_below_iff
  less_sprod           ~> below_sprod
  spair_less           ~> spair_below
  sfst_less_iff        ~> sfst_below_iff
  ssnd_less_iff        ~> ssnd_below_iff
  fix_least_less       ~> fix_least_below
  dist_less_one        ~> dist_below_one
  less_ONE             ~> below_ONE
  ONE_less_iff         ~> ONE_below_iff
  less_sinlD           ~> below_sinlD
  less_sinrD           ~> below_sinrD


*** FOL and ZF ***

* All constant names are now qualified internally and use proper
identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.


*** ML ***

* Antiquotation @{assert} inlines a function bool -> unit that raises
Fail if the argument is false.  Due to inlining the source position of
failed assertions is included in the error output.

* Discontinued antiquotation @{theory_ref}, which is obsolete since ML
text is in practice always evaluated with a stable theory checkpoint.
Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.

* Antiquotation @{theory A} refers to theory A from the ancestry of
the current context, not any accidental theory loader state as before.
Potential INCOMPATIBILITY, subtle change in semantics.

* Syntax.pretty_priority (default 0) configures the required priority
of pretty-printed output and thus affects insertion of parentheses.

* Syntax.default_root (default "any") configures the inner syntax
category (nonterminal symbol) for parsing of terms.

* Former exception Library.UnequalLengths now coincides with
ListPair.UnequalLengths.

* Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
main functionality is provided by structure Simplifier.

* Renamed raw "explode" function to "raw_explode" to emphasize its
meaning.  Note that internally to Isabelle, Symbol.explode is used in
almost all situations.

* Discontinued obsolete function sys_error and exception SYS_ERROR.
See implementation manual for further details on exceptions in
Isabelle/ML.

* Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
meaning.

* Renamed structure PureThy to Pure_Thy and moved most of its
operations to structure Global_Theory, to emphasize that this is
rarely-used global-only stuff.

* Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
instead (or tracing for high-volume output).

* Configuration option show_question_marks only affects regular pretty
printing of types and terms, not raw Term.string_of_vname.

* ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
INCOMPATIBILITY, superseded by static antiquotations @{thm} and
@{thms} for most purposes.

* ML structure Unsynchronized is never opened, not even in Isar
interaction mode as before.  Old Unsynchronized.set etc. have been
discontinued -- use plain := instead.  This should be *rare* anyway,
since modern tools always work via official context data, notably
configuration options.

* Parallel and asynchronous execution requires special care concerning
interrupts.  Structure Exn provides some convenience functions that
avoid working directly with raw Interrupt.  User code must not absorb
interrupts -- intermediate handling (for cleanup etc.) needs to be
followed by re-raising of the original exception.  Another common
source of mistakes are "handle _" patterns, which make the meaning of
the program subject to physical effects of the environment.



New in Isabelle2009-2 (June 2010)
---------------------------------

*** General ***

* Authentic syntax for *all* logical entities (type classes, type
constructors, term constants): provides simple and robust
correspondence between formal entities and concrete syntax.  Within
the parse tree / AST representations, "constants" are decorated by
their category (class, type, const) and spelled out explicitly with
their full internal name.

Substantial INCOMPATIBILITY concerning low-level syntax declarations
and translations (translation rules and translation functions in ML).
Some hints on upgrading:

  - Many existing uses of 'syntax' and 'translations' can be replaced
    by more modern 'type_notation', 'notation' and 'abbreviation',
    which are independent of this issue.

  - 'translations' require markup within the AST; the term syntax
    provides the following special forms:

      CONST c   -- produces syntax version of constant c from context
      XCONST c  -- literally c, checked as constant from context
      c         -- literally c, if declared by 'syntax'

    Plain identifiers are treated as AST variables -- occasionally the
    system indicates accidental variables via the error "rhs contains
    extra variables".

    Type classes and type constructors are marked according to their
    concrete syntax.  Some old translations rules need to be written
    for the "type" category, using type constructor application
    instead of pseudo-term application of the default category
    "logic".

  - 'parse_translation' etc. in ML may use the following
    antiquotations:

      @{class_syntax c}   -- type class c within parse tree / AST
      @{term_syntax c}    -- type constructor c within parse tree / AST
      @{const_syntax c}   -- ML version of "CONST c" above
      @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)

  - Literal types within 'typed_print_translations', i.e. those *not*
    represented as pseudo-terms are represented verbatim.  Use @{class
    c} or @{type_name c} here instead of the above syntax
    antiquotations.

Note that old non-authentic syntax was based on unqualified base
names, so all of the above "constant" names would coincide.  Recall
that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
diagnose syntax problems.

* Type constructors admit general mixfix syntax, not just infix.

* Concrete syntax may be attached to local entities without a proof
body, too.  This works via regular mixfix annotations for 'fix',
'def', 'obtain' etc. or via the explicit 'write' command, which is
similar to the 'notation' command in theory specifications.

* Discontinued unnamed infix syntax (legacy feature for many years) --
need to specify constant name and syntax separately.  Internal ML
datatype constructors have been renamed from InfixName to Infix etc.
Minor INCOMPATIBILITY.

* Schematic theorem statements need to be explicitly markup as such,
via commands 'schematic_lemma', 'schematic_theorem',
'schematic_corollary'.  Thus the relevance of the proof is made
syntactically clear, which impacts performance in a parallel or
asynchronous interactive environment.  Minor INCOMPATIBILITY.

* Use of cumulative prems via "!" in some proof methods has been
discontinued (old legacy feature).

* References 'trace_simp' and 'debug_simp' have been replaced by
configuration options stored in the context. Enabling tracing (the
case of debugging is similar) in proofs works via

  using [[trace_simp = true]]

Tracing is then active for all invocations of the simplifier in
subsequent goal refinement steps. Tracing may also still be enabled or
disabled via the ProofGeneral settings menu.

* Separate commands 'hide_class', 'hide_type', 'hide_const',
'hide_fact' replace the former 'hide' KIND command.  Minor
INCOMPATIBILITY.

* Improved parallelism of proof term normalization: usedir -p2 -q0 is
more efficient than combinations with -q1 or -q2.


*** Pure ***

* Proofterms record type-class reasoning explicitly, using the
"unconstrain" operation internally.  This eliminates all sort
constraints from a theorem and proof, introducing explicit
OFCLASS-premises.  On the proof term level, this operation is
automatically applied at theorem boundaries, such that closed proofs
are always free of sort constraints.  INCOMPATIBILITY for tools that
inspect proof terms.

* Local theory specifications may depend on extra type variables that
are not present in the result type -- arguments TYPE('a) :: 'a itself
are added internally.  For example:

  definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"

* Predicates of locales introduced by classes carry a mandatory
"class" prefix.  INCOMPATIBILITY.

* Vacuous class specifications observe default sort.  INCOMPATIBILITY.

* Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
'class' instead.

* Command 'code_reflect' allows to incorporate generated ML code into
runtime environment; replaces immature code_datatype antiquotation.
INCOMPATIBILITY.

* Code generator: simple concept for abstract datatypes obeying
invariants.

* Code generator: details of internal data cache have no impact on the
user space functionality any longer.

* Methods "unfold_locales" and "intro_locales" ignore non-locale
subgoals.  This is more appropriate for interpretations with 'where'.
INCOMPATIBILITY.

* Command 'example_proof' opens an empty proof body.  This allows to
experiment with Isar, without producing any persistent result.

* Commands 'type_notation' and 'no_type_notation' declare type syntax
within a local theory context, with explicit checking of the
constructors involved (in contrast to the raw 'syntax' versions).

* Commands 'types' and 'typedecl' now work within a local theory
context -- without introducing dependencies on parameters or
assumptions, which is not possible in Isabelle/Pure.

* Command 'defaultsort' has been renamed to 'default_sort', it works
within a local theory context.  Minor INCOMPATIBILITY.


*** HOL ***

* Command 'typedef' now works within a local theory context -- without
introducing dependencies on parameters or assumptions, which is not
possible in Isabelle/Pure/HOL.  Note that the logical environment may
contain multiple interpretations of local typedefs (with different
non-emptiness proofs), even in a global theory context.

* New package for quotient types.  Commands 'quotient_type' and
'quotient_definition' may be used for defining types and constants by
quotient constructions.  An example is the type of integers created by
quotienting pairs of natural numbers:

  fun
    intrel :: "(nat * nat) => (nat * nat) => bool"
  where
    "intrel (x, y) (u, v) = (x + v = u + y)"

  quotient_type int = "nat * nat" / intrel
    by (auto simp add: equivp_def expand_fun_eq)

  quotient_definition
    "0::int" is "(0::nat, 0::nat)"

The method "lifting" can be used to lift of theorems from the
underlying "raw" type to the quotient type.  The example
src/HOL/Quotient_Examples/FSet.thy includes such a quotient
construction and provides a reasoning infrastructure for finite sets.

* Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
clash with new theory Quotient in Main HOL.

* Moved the SMT binding into the main HOL session, eliminating
separate HOL-SMT session.

* List membership infix mem operation is only an input abbreviation.
INCOMPATIBILITY.

* Theory Library/Word.thy has been removed.  Use library Word/Word.thy
for future developements; former Library/Word.thy is still present in
the AFP entry RSAPPS.

* Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
longer shadowed.  INCOMPATIBILITY.

* Dropped theorem duplicate comp_arith; use semiring_norm instead.
INCOMPATIBILITY.

* Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
INCOMPATIBILITY.

* Dropped normalizing_semiring etc; use the facts in semiring classes
instead.  INCOMPATIBILITY.

* Dropped several real-specific versions of lemmas about floor and
ceiling; use the generic lemmas from theory "Archimedean_Field"
instead.  INCOMPATIBILITY.

  floor_number_of_eq         ~> floor_number_of
  le_floor_eq_number_of      ~> number_of_le_floor
  le_floor_eq_zero           ~> zero_le_floor
  le_floor_eq_one            ~> one_le_floor
  floor_less_eq_number_of    ~> floor_less_number_of
  floor_less_eq_zero         ~> floor_less_zero
  floor_less_eq_one          ~> floor_less_one
  less_floor_eq_number_of    ~> number_of_less_floor
  less_floor_eq_zero         ~> zero_less_floor
  less_floor_eq_one          ~> one_less_floor
  floor_le_eq_number_of      ~> floor_le_number_of
  floor_le_eq_zero           ~> floor_le_zero
  floor_le_eq_one            ~> floor_le_one
  floor_subtract_number_of   ~> floor_diff_number_of
  floor_subtract_one         ~> floor_diff_one
  ceiling_number_of_eq       ~> ceiling_number_of
  ceiling_le_eq_number_of    ~> ceiling_le_number_of
  ceiling_le_zero_eq         ~> ceiling_le_zero
  ceiling_le_eq_one          ~> ceiling_le_one
  less_ceiling_eq_number_of  ~> number_of_less_ceiling
  less_ceiling_eq_zero       ~> zero_less_ceiling
  less_ceiling_eq_one        ~> one_less_ceiling
  ceiling_less_eq_number_of  ~> ceiling_less_number_of
  ceiling_less_eq_zero       ~> ceiling_less_zero
  ceiling_less_eq_one        ~> ceiling_less_one
  le_ceiling_eq_number_of    ~> number_of_le_ceiling
  le_ceiling_eq_zero         ~> zero_le_ceiling
  le_ceiling_eq_one          ~> one_le_ceiling
  ceiling_subtract_number_of ~> ceiling_diff_number_of
  ceiling_subtract_one       ~> ceiling_diff_one

* Theory "Finite_Set": various folding_XXX locales facilitate the
application of the various fold combinators on finite sets.

* Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
provides abstract red-black tree type which is backed by "RBT_Impl" as
implementation.  INCOMPATIBILTY.

* Theory Library/Coinductive_List has been removed -- superseded by
AFP/thys/Coinductive.

* Theory PReal, including the type "preal" and related operations, has
been removed.  INCOMPATIBILITY.

* Real: new development using Cauchy Sequences.

* Split off theory "Big_Operators" containing setsum, setprod,
Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.

* Theory "Rational" renamed to "Rat", for consistency with "Nat",
"Int" etc.  INCOMPATIBILITY.

* Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.

* New set of rules "ac_simps" provides combined assoc / commute
rewrites for all interpretations of the appropriate generic locales.

* Renamed theory "OrderedGroup" to "Groups" and split theory
"Ring_and_Field" into theories "Rings" and "Fields"; for more
appropriate and more consistent names suitable for name prefixes
within the HOL theories.  INCOMPATIBILITY.

* Some generic constants have been put to appropriate theories:
  - less_eq, less: Orderings
  - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  - inverse, divide: Rings
INCOMPATIBILITY.

* More consistent naming of type classes involving orderings (and
lattices):

    lower_semilattice                   ~> semilattice_inf
    upper_semilattice                   ~> semilattice_sup

    dense_linear_order                  ~> dense_linorder

    pordered_ab_group_add               ~> ordered_ab_group_add
    pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
    pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
    pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
    pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
    pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
    pordered_cancel_semiring            ~> ordered_cancel_semiring
    pordered_comm_monoid_add            ~> ordered_comm_monoid_add
    pordered_comm_ring                  ~> ordered_comm_ring
    pordered_comm_semiring              ~> ordered_comm_semiring
    pordered_ring                       ~> ordered_ring
    pordered_ring_abs                   ~> ordered_ring_abs
    pordered_semiring                   ~> ordered_semiring

    ordered_ab_group_add                ~> linordered_ab_group_add
    ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
    ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
    ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
    ordered_field                       ~> linordered_field
    ordered_field_no_lb                 ~> linordered_field_no_lb
    ordered_field_no_ub                 ~> linordered_field_no_ub
    ordered_field_dense_linear_order    ~> dense_linordered_field
    ordered_idom                        ~> linordered_idom
    ordered_ring                        ~> linordered_ring
    ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
    ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
    ordered_ring_strict                 ~> linordered_ring_strict
    ordered_semidom                     ~> linordered_semidom
    ordered_semiring                    ~> linordered_semiring
    ordered_semiring_1                  ~> linordered_semiring_1
    ordered_semiring_1_strict           ~> linordered_semiring_1_strict
    ordered_semiring_strict             ~> linordered_semiring_strict

  The following slightly odd type classes have been moved to a
  separate theory Library/Lattice_Algebras:

    lordered_ab_group_add               ~> lattice_ab_group_add
    lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
    lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
    lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
    lordered_ring                       ~> lattice_ring

INCOMPATIBILITY.

* Refined field classes:
  - classes division_ring_inverse_zero, field_inverse_zero,
    linordered_field_inverse_zero include rule inverse 0 = 0 --
    subsumes former division_by_zero class;
  - numerous lemmas have been ported from field to division_ring.
INCOMPATIBILITY.

* Refined algebra theorem collections:
  - dropped theorem group group_simps, use algebra_simps instead;
  - dropped theorem group ring_simps, use field_simps instead;
  - proper theorem collection field_simps subsumes former theorem
    groups field_eq_simps and field_simps;
  - dropped lemma eq_minus_self_iff which is a duplicate for
    equal_neg_zero.
INCOMPATIBILITY.

* Theory Finite_Set and List: some lemmas have been generalized from
sets to lattices:

  fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  union_Union_fold_union        ~> sup_Sup_fold_sup
  Inter_fold_inter              ~> Inf_fold_inf
  Union_fold_union              ~> Sup_fold_sup
  inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  union_UNION_fold_union        ~> sup_SUPR_fold_sup
  INTER_fold_inter              ~> INFI_fold_inf
  UNION_fold_union              ~> SUPR_fold_sup

* Theory "Complete_Lattice": lemmas top_def and bot_def have been
replaced by the more convenient lemmas Inf_empty and Sup_empty.
Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.

* Reorganized theory Multiset: swapped notation of pointwise and
multiset order:

  - pointwise ordering is instance of class order with standard syntax
    <= and <;
  - multiset ordering has syntax <=# and <#; partial order properties
    are provided by means of interpretation with prefix
    multiset_order;
  - less duplication, less historical organization of sections,
    conversion from associations lists to multisets, rudimentary code
    generation;
  - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
    if needed.

Renamed:

  multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  multi_count_ext  ~>  multiset_ext
  diff_union_inverse2  ~>  diff_union_cancelR

INCOMPATIBILITY.

* Theory Permutation: replaced local "remove" by List.remove1.

* Code generation: ML and OCaml code is decorated with signatures.

* Theory List: added transpose.

* Library/Nat_Bijection.thy is a collection of bijective functions
between nat and other types, which supersedes the older libraries
Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.

  Constants:
  Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  Countable.pair_encode           ~> prod_encode
  NatIso.prod2nat                 ~> prod_encode
  NatIso.nat2prod                 ~> prod_decode
  NatIso.sum2nat                  ~> sum_encode
  NatIso.nat2sum                  ~> sum_decode
  NatIso.list2nat                 ~> list_encode
  NatIso.nat2list                 ~> list_decode
  NatIso.set2nat                  ~> set_encode
  NatIso.nat2set                  ~> set_decode

  Lemmas:
  Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode

* Sledgehammer:
  - Renamed ATP commands:
    atp_info     ~> sledgehammer running_atps
    atp_kill     ~> sledgehammer kill_atps
    atp_messages ~> sledgehammer messages
    atp_minimize ~> sledgehammer minimize
    print_atps   ~> sledgehammer available_atps
    INCOMPATIBILITY.
  - Added user's manual ("isabelle doc sledgehammer").
  - Added option syntax and "sledgehammer_params" to customize
    Sledgehammer's behavior.  See the manual for details.
  - Modified the Isar proof reconstruction code so that it produces
    direct proofs rather than proofs by contradiction.  (This feature
    is still experimental.)
  - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
    full-typed mode.
  - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.

* Nitpick:
  - Added and implemented "binary_ints" and "bits" options.
  - Added "std" option and implemented support for nonstandard models.
  - Added and implemented "finitize" option to improve the precision
    of infinite datatypes based on a monotonicity analysis.
  - Added support for quotient types.
  - Added support for "specification" and "ax_specification"
    constructs.
  - Added support for local definitions (for "function" and
    "termination" proofs).
  - Added support for term postprocessors.
  - Optimized "Multiset.multiset" and "FinFun.finfun".
  - Improved efficiency of "destroy_constrs" optimization.
  - Fixed soundness bugs related to "destroy_constrs" optimization and
    record getters.
  - Fixed soundness bug related to higher-order constructors.
  - Fixed soundness bug when "full_descrs" is enabled.
  - Improved precision of set constructs.
  - Added "atoms" option.
  - Added cache to speed up repeated Kodkod invocations on the same
    problems.
  - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
    "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
    "SAT4J_Light".  INCOMPATIBILITY.
  - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
    "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.

* Method "induct" now takes instantiations of the form t, where t is not
  a variable, as a shorthand for "x == t", where x is a fresh variable.
  If this is not intended, t has to be enclosed in parentheses.
  By default, the equalities generated by definitional instantiations
  are pre-simplified, which may cause parameters of inductive cases
  to disappear, or may even delete some of the inductive cases.
  Use "induct (no_simp)" instead of "induct" to restore the old
  behaviour. The (no_simp) option is also understood by the "cases"
  and "nominal_induct" methods, which now perform pre-simplification, too.
  INCOMPATIBILITY.


*** HOLCF ***

* Variable names in lemmas generated by the domain package have
changed; the naming scheme is now consistent with the HOL datatype
package.  Some proof scripts may be affected, INCOMPATIBILITY.

* The domain package no longer defines the function "foo_copy" for
recursive domain "foo".  The reach lemma is now stated directly in
terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
be reformulated in terms of "foo_take", INCOMPATIBILITY.

* Most definedness lemmas generated by the domain package (previously
of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
like "foo$x = UU <-> x = UU", which works better as a simp rule.
Proofs that used definedness lemmas as intro rules may break,
potential INCOMPATIBILITY.

* Induction and casedist rules generated by the domain package now
declare proper case_names (one called "bottom", and one named for each
constructor).  INCOMPATIBILITY.

* For mutually-recursive domains, separate "reach" and "take_lemma"
rules are generated for each domain, INCOMPATIBILITY.

  foo_bar.reach       ~> foo.reach  bar.reach
  foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma

* Some lemmas generated by the domain package have been renamed for
consistency with the datatype package, INCOMPATIBILITY.

  foo.ind        ~> foo.induct
  foo.finite_ind ~> foo.finite_induct
  foo.coind      ~> foo.coinduct
  foo.casedist   ~> foo.exhaust
  foo.exhaust    ~> foo.nchotomy

* For consistency with other definition packages, the fixrec package
now generates qualified theorem names, INCOMPATIBILITY.

  foo_simps  ~> foo.simps
  foo_unfold ~> foo.unfold
  foo_induct ~> foo.induct

* The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
method and internal fixrec proofs now use the default simpset instead.
INCOMPATIBILITY.

* The "contlub" predicate has been removed.  Proof scripts should use
lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.

* The "admw" predicate has been removed, INCOMPATIBILITY.

* The constants cpair, cfst, and csnd have been removed in favor of
Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.


*** ML ***

* Antiquotations for basic formal entities:

    @{class NAME}         -- type class
    @{class_syntax NAME}  -- syntax representation of the above

    @{type_name NAME}     -- logical type
    @{type_abbrev NAME}   -- type abbreviation
    @{nonterminal NAME}   -- type of concrete syntactic category
    @{type_syntax NAME}   -- syntax representation of any of the above

    @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
    @{const_abbrev NAME}  -- abbreviated constant
    @{const_syntax NAME}  -- syntax representation of any of the above

* Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
syntax constant (cf. 'syntax' command).

* Antiquotation @{make_string} inlines a function to print arbitrary
values similar to the ML toplevel.  The result is compiler dependent
and may fall back on "?" in certain situations.

* Diagnostic commands 'ML_val' and 'ML_command' may refer to
antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
Isar.state() and Isar.goal(), which belong to the old TTY loop and do
not work with the asynchronous Isar document model.

* Configuration options now admit dynamic default values, depending on
the context or even global references.

* SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
uses an efficient external library if available (for Poly/ML).

* Renamed some important ML structures, while keeping the old names
for some time as aliases within the structure Legacy:

  OuterKeyword  ~>  Keyword
  OuterLex      ~>  Token
  OuterParse    ~>  Parse
  OuterSyntax   ~>  Outer_Syntax
  PrintMode     ~>  Print_Mode
  SpecParse     ~>  Parse_Spec
  ThyInfo       ~>  Thy_Info
  ThyLoad       ~>  Thy_Load
  ThyOutput     ~>  Thy_Output
  TypeInfer     ~>  Type_Infer

Note that "open Legacy" simplifies porting of sources, but forgetting
to remove it again will complicate porting again in the future.

* Most operations that refer to a global context are named
accordingly, e.g. Simplifier.global_context or
ProofContext.init_global.  There are some situations where a global
context actually works, but under normal circumstances one needs to
pass the proper local context through the code!

* Discontinued old TheoryDataFun with its copy/init operation -- data
needs to be pure.  Functor Theory_Data_PP retains the traditional
Pretty.pp argument to merge, which is absent in the standard
Theory_Data version.

* Sorts.certify_sort and derived "cert" operations for types and terms
no longer minimize sorts.  Thus certification at the boundary of the
inference kernel becomes invariant under addition of class relations,
which is an important monotonicity principle.  Sorts are now minimized
in the syntax layer only, at the boundary between the end-user and the
system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
explicitly in rare situations.

* Renamed old-style Drule.standard to Drule.export_without_context, to
emphasize that this is in no way a standard operation.
INCOMPATIBILITY.

* Subgoal.FOCUS (and variants): resulting goal state is normalized as
usual for resolution.  Rare INCOMPATIBILITY.

* Renamed varify/unvarify operations to varify_global/unvarify_global
to emphasize that these only work in a global situation (which is
quite rare).

* Curried take and drop in library.ML; negative length is interpreted
as infinity (as in chop).  Subtle INCOMPATIBILITY.

* Proof terms: type substitutions on proof constants now use canonical
order of type variables.  INCOMPATIBILITY for tools working with proof
terms.

* Raw axioms/defs may no longer carry sort constraints, and raw defs
may no longer carry premises.  User-level specifications are
transformed accordingly by Thm.add_axiom/add_def.


*** System ***

* Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
proof terms are enabled unconditionally in the new HOL-Proofs image.

* Discontinued old ISABELLE and ISATOOL environment settings (legacy
feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
respectively.

* Old lib/scripts/polyml-platform is superseded by the
ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
variant, even on a 64 bit machine.  The following example setting
prefers 64 bit if available:

  ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"

* The preliminary Isabelle/jEdit application demonstrates the emerging
Isabelle/Scala layer for advanced prover interaction and integration.
See src/Tools/jEdit or "isabelle jedit" provided by the properly built
component.

* "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
similar to the default assignment of the document preparation system
(cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
provides some operations for direct access to the font without asking
the user for manual installation.



New in Isabelle2009-1 (December 2009)
-------------------------------------

*** General ***

* Discontinued old form of "escaped symbols" such as \\<forall>.  Only
one backslash should be used, even in ML sources.


*** Pure ***

* Locale interpretation propagates mixins along the locale hierarchy.
The currently only available mixins are the equations used to map
local definitions to terms of the target domain of an interpretation.

* Reactivated diagnostic command 'print_interps'.  Use "print_interps
loc" to print all interpretations of locale "loc" in the theory.
Interpretations in proofs are not shown.

* Thoroughly revised locales tutorial.  New section on conditional
interpretation.

* On instantiation of classes, remaining undefined class parameters
are formally declared.  INCOMPATIBILITY.


*** Document preparation ***

* New generalized style concept for printing terms: @{foo (style) ...}
instead of @{foo_style style ...}  (old form is still retained for
backward compatibility).  Styles can be also applied for
antiquotations prop, term_type and typeof.


*** HOL ***

* New proof method "smt" for a combination of first-order logic with
equality, linear and nonlinear (natural/integer/real) arithmetic, and
fixed-size bitvectors; there is also basic support for higher-order
features (esp. lambda abstractions).  It is an incomplete decision
procedure based on external SMT solvers using the oracle mechanism;
for the SMT solver Z3, this method is proof-producing.  Certificates
are provided to avoid calling the external solvers solely for
re-checking proofs.  Due to a remote SMT service there is no need for
installing SMT solvers locally.  See src/HOL/SMT.

* New commands to load and prove verification conditions generated by
the Boogie program verifier or derived systems (e.g. the Verifying C
Compiler (VCC) or Spec#).  See src/HOL/Boogie.

* New counterexample generator tool 'nitpick' based on the Kodkod
relational model finder.  See src/HOL/Tools/Nitpick and
src/HOL/Nitpick_Examples.

* New commands 'code_pred' and 'values' to invoke the predicate
compiler and to enumerate values of inductive predicates.

* A tabled implementation of the reflexive transitive closure.

* New implementation of quickcheck uses generic code generator;
default generators are provided for all suitable HOL types, records
and datatypes.  Old quickcheck can be re-activated importing theory
Library/SML_Quickcheck.

* New testing tool Mirabelle for automated proof tools.  Applies
several tools and tactics like sledgehammer, metis, or quickcheck, to
every proof step in a theory.  To be used in batch mode via the
"mirabelle" utility.

* New proof method "sos" (sum of squares) for nonlinear real
arithmetic (originally due to John Harison). It requires theory
Library/Sum_Of_Squares.  It is not a complete decision procedure but
works well in practice on quantifier-free real arithmetic with +, -,
*, ^, =, <= and <, i.e. boolean combinations of equalities and
inequalities between polynomials.  It makes use of external
semidefinite programming solvers.  Method "sos" generates a
certificate that can be pasted into the proof thus avoiding the need
to call an external tool every time the proof is checked.  See
src/HOL/Library/Sum_Of_Squares.

* New method "linarith" invokes existing linear arithmetic decision
procedure only.

* New command 'atp_minimal' reduces result produced by Sledgehammer.

* New Sledgehammer option "Full Types" in Proof General settings menu.
Causes full type information to be output to the ATPs.  This slows
ATPs down considerably but eliminates a source of unsound "proofs"
that fail later.

* New method "metisFT": A version of metis that uses full type
information in order to avoid failures of proof reconstruction.

* New evaluator "approximate" approximates an real valued term using
the same method as the approximation method.

* Method "approximate" now supports arithmetic expressions as
boundaries of intervals and implements interval splitting and Taylor
series expansion.

* ML antiquotation @{code_datatype} inserts definition of a datatype
generated by the code generator; e.g. see src/HOL/Predicate.thy.

* New theory SupInf of the supremum and infimum operators for sets of
reals.

* New theory Probability, which contains a development of measure
theory, eventually leading to Lebesgue integration and probability.

* Extended Multivariate Analysis to include derivation and Brouwer's
fixpoint theorem.

* Reorganization of number theory, INCOMPATIBILITY:
  - new number theory development for nat and int, in theories Divides
    and GCD as well as in new session Number_Theory
  - some constants and facts now suffixed with _nat and _int
    accordingly
  - former session NumberTheory now named Old_Number_Theory, including
    theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  - moved theory Pocklington from src/HOL/Library to
    src/HOL/Old_Number_Theory

* Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
lcm of finite and infinite sets. It is shown that they form a complete
lattice.

* Class semiring_div requires superclass no_zero_divisors and proof of
div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
generalized to class semiring_div, subsuming former theorems
zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
INCOMPATIBILITY.

* Refinements to lattice classes and sets:
  - less default intro/elim rules in locale variant, more default
    intro/elim rules in class variant: more uniformity
  - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
    le_inf_iff
  - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
    sup_aci)
  - renamed ACI to inf_sup_aci
  - new class "boolean_algebra"
  - class "complete_lattice" moved to separate theory
    "Complete_Lattice"; corresponding constants (and abbreviations)
    renamed and with authentic syntax:
    Set.Inf ~>    Complete_Lattice.Inf
    Set.Sup ~>    Complete_Lattice.Sup
    Set.INFI ~>   Complete_Lattice.INFI
    Set.SUPR ~>   Complete_Lattice.SUPR
    Set.Inter ~>  Complete_Lattice.Inter
    Set.Union ~>  Complete_Lattice.Union
    Set.INTER ~>  Complete_Lattice.INTER
    Set.UNION ~>  Complete_Lattice.UNION
  - authentic syntax for
    Set.Pow
    Set.image
  - mere abbreviations:
    Set.empty               (for bot)
    Set.UNIV                (for top)
    Set.inter               (for inf, formerly Set.Int)
    Set.union               (for sup, formerly Set.Un)
    Complete_Lattice.Inter  (for Inf)
    Complete_Lattice.Union  (for Sup)
    Complete_Lattice.INTER  (for INFI)
    Complete_Lattice.UNION  (for SUPR)
  - object-logic definitions as far as appropriate

INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
Un_subset_iff are explicitly deleted as default simp rules; then also
their lattice counterparts le_inf_iff and le_sup_iff have to be
deleted to achieve the desired effect.

* Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
rules by default any longer; the same applies to min_max.inf_absorb1
etc.  INCOMPATIBILITY.

* Rules sup_Int_eq and sup_Un_eq are no longer declared as
pred_set_conv by default.  INCOMPATIBILITY.

* Power operations on relations and functions are now one dedicated
constant "compow" with infix syntax "^^".  Power operation on
multiplicative monoids retains syntax "^" and is now defined generic
in class power.  INCOMPATIBILITY.

* Relation composition "R O S" now has a more standard argument order:
"R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
break, since the O_assoc rule was not rewritten like this.  Fix using
O_assoc[symmetric].  The same applies to the curried version "R OO S".

* Function "Inv" is renamed to "inv_into" and function "inv" is now an
abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
INCOMPATIBILITY.

* Most rules produced by inductive and datatype package have mandatory
prefixes.  INCOMPATIBILITY.

* Changed "DERIV_intros" to a dynamic fact, which can be augmented by
the attribute of the same name.  Each of the theorems in the list
DERIV_intros assumes composition with an additional function and
matches a variable to the derivative, which has to be solved by the
Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
of most elementary terms.  Former Maclauren.DERIV_tac and
Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
INCOMPATIBILITY.

* Code generator attributes follow the usual underscore convention:
    code_unfold     replaces    code unfold
    code_post       replaces    code post
    etc.
  INCOMPATIBILITY.

* Renamed methods:
    sizechange -> size_change
    induct_scheme -> induction_schema
  INCOMPATIBILITY.

* Discontinued abbreviation "arbitrary" of constant "undefined".
INCOMPATIBILITY, use "undefined" directly.

* Renamed theorems:
    Suc_eq_add_numeral_1 -> Suc_eq_plus1
    Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
    Suc_plus1 -> Suc_eq_plus1
    *anti_sym -> *antisym*
    vector_less_eq_def -> vector_le_def
  INCOMPATIBILITY.

* Added theorem List.map_map as [simp].  Removed List.map_compose.
INCOMPATIBILITY.

* Removed predicate "M hassize n" (<--> card M = n & finite M).
INCOMPATIBILITY.


*** HOLCF ***

* Theory Representable defines a class "rep" of domains that are
representable (via an ep-pair) in the universal domain type "udom".
Instances are provided for all type constructors defined in HOLCF.

* The 'new_domain' command is a purely definitional version of the
domain package, for representable domains.  Syntax is identical to the
old domain package.  The 'new_domain' package also supports indirect
recursion using previously-defined type constructors.  See
src/HOLCF/ex/New_Domain.thy for examples.

* Method "fixrec_simp" unfolds one step of a fixrec-defined constant
on the left-hand side of an equation, and then performs
simplification.  Rewriting is done using rules declared with the
"fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.

* The pattern-match compiler in 'fixrec' can now handle constructors
with HOL function types.  Pattern-match combinators for the Pair
constructor are pre-configured.

* The 'fixrec' package now produces better fixed-point induction rules
for mutually-recursive definitions:  Induction rules have conclusions
of the form "P foo bar" instead of "P <foo, bar>".

* The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
been renamed to "below".  The name "below" now replaces "less" in many
theorem names.  (Legacy theorem names using "less" are still supported
as well.)

* The 'fixrec' package now supports "bottom patterns".  Bottom
patterns can be used to generate strictness rules, or to make
functions more strict (much like the bang-patterns supported by the
Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
examples.


*** ML ***

* Support for Poly/ML 5.3.0, with improved reporting of compiler
errors and run-time exceptions, including detailed source positions.

* Structure Name_Space (formerly NameSpace) now manages uniquely
identified entries, with some additional information such as source
position, logical grouping etc.

* Theory and context data is now introduced by the simplified and
modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
to be pure, but the old TheoryDataFun for mutable data (with explicit
copy operation) is still available for some time.

* Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
provides a high-level programming interface to synchronized state
variables with atomic update.  This works via pure function
application within a critical section -- its runtime should be as
short as possible; beware of deadlocks if critical code is nested,
either directly or indirectly via other synchronized variables!

* Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
wraps raw ML references, explicitly indicating their non-thread-safe
behaviour.  The Isar toplevel keeps this structure open, to
accommodate Proof General as well as quick and dirty interactive
experiments with references.

* PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
parallel tactical reasoning.

* Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
are similar to SUBPROOF, but are slightly more flexible: only the
specified parts of the subgoal are imported into the context, and the
body tactic may introduce new subgoals and schematic variables.

* Old tactical METAHYPS, which does not observe the proof context, has
been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
or Subgoal.FOCUS etc.

* Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
functors have their own ML name space there is no point to mark them
separately.)  Minor INCOMPATIBILITY.

* Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.

* Renamed several structures FooBar to Foo_Bar.  Occasional,
INCOMPATIBILITY.

* Operations of structure Skip_Proof no longer require quick_and_dirty
mode, which avoids critical setmp.

* Eliminated old Attrib.add_attributes, Method.add_methods and related
combinators for "args".  INCOMPATIBILITY, need to use simplified
Attrib/Method.setup introduced in Isabelle2009.

* Proper context for simpset_of, claset_of, clasimpset_of.  May fall
back on global_simpset_of, global_claset_of, global_clasimpset_of as
last resort.  INCOMPATIBILITY.

* Display.pretty_thm now requires a proper context (cf. former
ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
or even Display.pretty_thm_without_context as last resort.
INCOMPATIBILITY.

* Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
Syntax.pretty_typ/term directly, preferably with proper context
instead of global theory.


*** System ***

* Further fine tuning of parallel proof checking, scales up to 8 cores
(max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
usedir option -q.

* Support for additional "Isabelle components" via etc/components, see
also the system manual.

* The isabelle makeall tool now operates on all components with
IsaMakefile, not just hardwired "logics".

* Removed "compress" option from isabelle-process and isabelle usedir;
this is always enabled.

* Discontinued support for Poly/ML 4.x versions.

* Isabelle tool "wwwfind" provides web interface for 'find_theorems'
on a given logic image.  This requires the lighttpd webserver and is
currently supported on Linux only.



New in Isabelle2009 (April 2009)
--------------------------------

*** General ***

* Simplified main Isabelle executables, with less surprises on
case-insensitive file-systems (such as Mac OS).

  - The main Isabelle tool wrapper is now called "isabelle" instead of
    "isatool."

  - The former "isabelle" alias for "isabelle-process" has been
    removed (should rarely occur to regular users).

  - The former "isabelle-interface" and its alias "Isabelle" have been
    removed (interfaces are now regular Isabelle tools).

Within scripts and make files, the Isabelle environment variables
ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
respectively.  (The latter are still available as legacy feature.)

The old isabelle-interface wrapper could react in confusing ways if
the interface was uninstalled or changed otherwise.  Individual
interface tool configuration is now more explicit, see also the
Isabelle system manual.  In particular, Proof General is now available
via "isabelle emacs".

INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
purge installed copies of Isabelle executables and re-run "isabelle
install -p ...", or use symlinks.

* The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
old ~/isabelle, which was slightly non-standard and apt to cause
surprises on case-insensitive file-systems (such as Mac OS).

INCOMPATIBILITY, need to move existing ~/isabelle/etc,
~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
care is required when using older releases of Isabelle.  Note that
ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
Isabelle distribution, in order to use the new ~/.isabelle uniformly.

* Proofs of fully specified statements are run in parallel on
multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
a regular 4-core machine, if the initial heap space is made reasonably
large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)

* The main reference manuals ("isar-ref", "implementation", and
"system") have been updated and extended.  Formally checked references
as hyperlinks are now available uniformly.


*** Pure ***

* Complete re-implementation of locales.  INCOMPATIBILITY in several
respects.  The most important changes are listed below.  See the
Tutorial on Locales ("locales" manual) for details.

- In locale expressions, instantiation replaces renaming.  Parameters
must be declared in a for clause.  To aid compatibility with previous
parameter inheritance, in locale declarations, parameters that are not
'touched' (instantiation position "_" or omitted) are implicitly added
with their syntax at the beginning of the for clause.

- Syntax from abbreviations and definitions in locales is available in
locale expressions and context elements.  The latter is particularly
useful in locale declarations.

- More flexible mechanisms to qualify names generated by locale
expressions.  Qualifiers (prefixes) may be specified in locale
expressions, and can be marked as mandatory (syntax: "name!:") or
optional (syntax "name?:").  The default depends for plain "name:"
depends on the situation where a locale expression is used: in
commands 'locale' and 'sublocale' prefixes are optional, in
'interpretation' and 'interpret' prefixes are mandatory.  The old
implicit qualifiers derived from the parameter names of a locale are
no longer generated.

- Command "sublocale l < e" replaces "interpretation l < e".  The
instantiation clause in "interpretation" and "interpret" (square
brackets) is no longer available.  Use locale expressions.

- When converting proof scripts, mandatory qualifiers in
'interpretation' and 'interpret' should be retained by default, even
if this is an INCOMPATIBILITY compared to former behavior.  In the
worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
in locale expressions range over a single locale instance only.

- Dropped locale element "includes".  This is a major INCOMPATIBILITY.
In existing theorem specifications replace the includes element by the
respective context elements of the included locale, omitting those
that are already present in the theorem specification.  Multiple
assume elements of a locale should be replaced by a single one
involving the locale predicate.  In the proof body, declarations (most
notably theorems) may be regained by interpreting the respective
locales in the proof context as required (command "interpret").

If using "includes" in replacement of a target solely because the
parameter types in the theorem are not as general as in the target,
consider declaring a new locale with additional type constraints on
the parameters (context element "constrains").

- Discontinued "locale (open)".  INCOMPATIBILITY.

- Locale interpretation commands no longer attempt to simplify goal.
INCOMPATIBILITY: in rare situations the generated goal differs.  Use
methods intro_locales and unfold_locales to clarify.

- Locale interpretation commands no longer accept interpretation
attributes.  INCOMPATIBILITY.

* Class declaration: so-called "base sort" must not be given in import
list any longer, but is inferred from the specification.  Particularly
in HOL, write

    class foo = ...

instead of

    class foo = type + ...

* Class target: global versions of theorems stemming do not carry a
parameter prefix any longer.  INCOMPATIBILITY.

* Class 'instance' command no longer accepts attached definitions.
INCOMPATIBILITY, use proper 'instantiation' target instead.

* Recovered hiding of consts, which was accidentally broken in
Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
makes c inaccessible; consider using ``hide (open) const c'' instead.

* Slightly more coherent Pure syntax, with updated documentation in
isar-ref manual.  Removed locales meta_term_syntax and
meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
INCOMPATIBILITY in rare situations.  Note that &&& should not be used
directly in regular applications.

* There is a new syntactic category "float_const" for signed decimal
fractions (e.g. 123.45 or -123.45).

* Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
interface with 'setup' command instead.

* Command 'local_setup' is similar to 'setup', but operates on a local
theory context.

* The 'axiomatization' command now only works within a global theory
context.  INCOMPATIBILITY.

* Goal-directed proof now enforces strict proof irrelevance wrt. sort
hypotheses.  Sorts required in the course of reasoning need to be
covered by the constraints in the initial statement, completed by the
type instance information of the background theory.  Non-trivial sort
hypotheses, which rarely occur in practice, may be specified via
vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:

  lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...

The result contains an implicit sort hypotheses as before --
SORT_CONSTRAINT premises are eliminated as part of the canonical rule
normalization.

* Generalized Isar history, with support for linear undo, direct state
addressing etc.

* Changed defaults for unify configuration options:

  unify_trace_bound = 50 (formerly 25)
  unify_search_bound = 60 (formerly 30)

* Different bookkeeping for code equations (INCOMPATIBILITY):

  a) On theory merge, the last set of code equations for a particular
     constant is taken (in accordance with the policy applied by other
     parts of the code generator framework).

  b) Code equations stemming from explicit declarations (e.g. code
     attribute) gain priority over default code equations stemming
     from definition, primrec, fun etc.

* Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.

* Unified theorem tables for both code generators.  Thus [code
func] has disappeared and only [code] remains.  INCOMPATIBILITY.

* Command 'find_consts' searches for constants based on type and name
patterns, e.g.

    find_consts "_ => bool"

By default, matching is against subtypes, but it may be restricted to
the whole type.  Searching by name is possible.  Multiple queries are
conjunctive and queries may be negated by prefixing them with a
hyphen:

    find_consts strict: "_ => bool" name: "Int" -"int => int"

* New 'find_theorems' criterion "solves" matches theorems that
directly solve the current goal (modulo higher-order unification).

* Auto solve feature for main theorem statements: whenever a new goal
is stated, "find_theorems solves" is called; any theorems that could
solve the lemma directly are listed as part of the goal state.
Cf. associated options in Proof General Isabelle settings menu,
enabled by default, with reasonable timeout for pathological cases of
higher-order unification.


*** Document preparation ***

* Antiquotation @{lemma} now imitates a regular terminal proof,
demanding keyword 'by' and supporting the full method expression
syntax just like the Isar command 'by'.


*** HOL ***

* Integrated main parts of former image HOL-Complex with HOL.  Entry
points Main and Complex_Main remain as before.

* Logic image HOL-Plain provides a minimal HOL with the most important
tools available (inductive, datatype, primrec, ...).  This facilitates
experimentation and tool development.  Note that user applications
(and library theories) should never refer to anything below theory
Main, as before.

* Logic image HOL-Main stops at theory Main, and thus facilitates
experimentation due to shorter build times.

* Logic image HOL-NSA contains theories of nonstandard analysis which
were previously part of former HOL-Complex.  Entry point Hyperreal
remains valid, but theories formerly using Complex_Main should now use
new entry point Hypercomplex.

* Generic ATP manager for Sledgehammer, based on ML threads instead of
Posix processes.  Avoids potentially expensive forking of the ML
process.  New thread-based implementation also works on non-Unix
platforms (Cygwin).  Provers are no longer hardwired, but defined
within the theory via plain ML wrapper functions.  Basic Sledgehammer
commands are covered in the isar-ref manual.

* Wrapper scripts for remote SystemOnTPTP service allows to use
sledgehammer without local ATP installation (Vampire etc.). Other
provers may be included via suitable ML wrappers, see also
src/HOL/ATP_Linkup.thy.

* ATP selection (E/Vampire/Spass) is now via Proof General's settings
menu.

* The metis method no longer fails because the theorem is too trivial
(contains the empty clause).

* The metis method now fails in the usual manner, rather than raising
an exception, if it determines that it cannot prove the theorem.

* Method "coherent" implements a prover for coherent logic (see also
src/Tools/coherent.ML).

* Constants "undefined" and "default" replace "arbitrary".  Usually
"undefined" is the right choice to replace "arbitrary", though
logically there is no difference.  INCOMPATIBILITY.

* Command "value" now integrates different evaluation mechanisms.  The
result of the first successful evaluation mechanism is printed.  In
square brackets a particular named evaluation mechanisms may be
specified (currently, [SML], [code] or [nbe]).  See further
src/HOL/ex/Eval_Examples.thy.

* Normalization by evaluation now allows non-leftlinear equations.
Declare with attribute [code nbe].

* Methods "case_tac" and "induct_tac" now refer to the very same rules
as the structured Isar versions "cases" and "induct", cf. the
corresponding "cases" and "induct" attributes.  Mutual induction rules
are now presented as a list of individual projections
(e.g. foo_bar.inducts for types foo and bar); the old format with
explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
rare situations a different rule is selected --- notably nested tuple
elimination instead of former prod.exhaust: use explicit (case_tac t
rule: prod.exhaust) here.

* Attributes "cases", "induct", "coinduct" support "del" option.

* Removed fact "case_split_thm", which duplicates "case_split".

* The option datatype has been moved to a new theory Option.  Renamed
option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.

* New predicate "strict_mono" classifies strict functions on partial
orders.  With strict functions on linear orders, reasoning about
(in)equalities is facilitated by theorems "strict_mono_eq",
"strict_mono_less_eq" and "strict_mono_less".

* Some set operations are now proper qualified constants with
authentic syntax.  INCOMPATIBILITY:

    op Int ~>   Set.Int
    op Un ~>    Set.Un
    INTER ~>    Set.INTER
    UNION ~>    Set.UNION
    Inter ~>    Set.Inter
    Union ~>    Set.Union
    {} ~>       Set.empty
    UNIV ~>     Set.UNIV

* Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
theory Set.

* Auxiliary class "itself" has disappeared -- classes without any
parameter are treated as expected by the 'class' command.

* Leibnitz's Series for Pi and the arcus tangens and logarithm series.

* Common decision procedures (Cooper, MIR, Ferrack, Approximation,
Dense_Linear_Order) are now in directory HOL/Decision_Procs.

* Theory src/HOL/Decision_Procs/Approximation provides the new proof
method "approximation".  It proves formulas on real values by using
interval arithmetic.  In the formulas are also the transcendental
functions sin, cos, tan, atan, ln, exp and the constant pi are
allowed. For examples see
src/HOL/Descision_Procs/ex/Approximation_Ex.thy.

* Theory "Reflection" now resides in HOL/Library.

* Entry point to Word library now simply named "Word".
INCOMPATIBILITY.

* Made source layout more coherent with logical distribution
structure:

    src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
    src/HOL/Library/Code_Message.thy ~> src/HOL/
    src/HOL/Library/GCD.thy ~> src/HOL/
    src/HOL/Library/Order_Relation.thy ~> src/HOL/
    src/HOL/Library/Parity.thy ~> src/HOL/
    src/HOL/Library/Univ_Poly.thy ~> src/HOL/
    src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
    src/HOL/Real/Lubs.thy ~> src/HOL/
    src/HOL/Real/PReal.thy ~> src/HOL/
    src/HOL/Real/Rational.thy ~> src/HOL/
    src/HOL/Real/RComplete.thy ~> src/HOL/
    src/HOL/Real/RealDef.thy ~> src/HOL/
    src/HOL/Real/RealPow.thy ~> src/HOL/
    src/HOL/Real/Real.thy ~> src/HOL/
    src/HOL/Complex/Complex_Main.thy ~> src/HOL/
    src/HOL/Complex/Complex.thy ~> src/HOL/
    src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
    src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
    src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
    src/HOL/Hyperreal/Fact.thy ~> src/HOL/
    src/HOL/Hyperreal/Integration.thy ~> src/HOL/
    src/HOL/Hyperreal/Lim.thy ~> src/HOL/
    src/HOL/Hyperreal/Ln.thy ~> src/HOL/
    src/HOL/Hyperreal/Log.thy ~> src/HOL/
    src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
    src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
    src/HOL/Hyperreal/Series.thy ~> src/HOL/
    src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
    src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
    src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
    src/HOL/Real/Float ~> src/HOL/Library/
    src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
    src/HOL/Real/RealVector.thy ~> src/HOL/

    src/HOL/arith_data.ML ~> src/HOL/Tools
    src/HOL/hologic.ML ~> src/HOL/Tools
    src/HOL/simpdata.ML ~> src/HOL/Tools
    src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
    src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
    src/HOL/nat_simprocs.ML ~> src/HOL/Tools
    src/HOL/Real/float_arith.ML ~> src/HOL/Tools
    src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
    src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
    src/HOL/Real/real_arith.ML ~> src/HOL/Tools

    src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
    src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
    src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
    src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
    src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
    src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL

* If methods "eval" and "evaluation" encounter a structured proof
state with !!/==>, only the conclusion is evaluated to True (if
possible), avoiding strange error messages.

* Method "sizechange" automates termination proofs using (a
modification of) the size-change principle.  Requires SAT solver.  See
src/HOL/ex/Termination.thy for examples.

* Simplifier: simproc for let expressions now unfolds if bound
variable occurs at most once in let expression body.  INCOMPATIBILITY.

* Method "arith": Linear arithmetic now ignores all inequalities when
fast_arith_neq_limit is exceeded, instead of giving up entirely.

* New attribute "arith" for facts that should always be used
automatically by arithmetic. It is intended to be used locally in
proofs, e.g.

  assumes [arith]: "x > 0"

Global usage is discouraged because of possible performance impact.

* New classes "top" and "bot" with corresponding operations "top" and
"bot" in theory Orderings; instantiation of class "complete_lattice"
requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.

* Changed definition lemma "less_fun_def" in order to provide an
instance for preorders on functions; use lemma "less_le" instead.
INCOMPATIBILITY.

* Theory Orderings: class "wellorder" moved here, with explicit
induction rule "less_induct" as assumption.  For instantiation of
"wellorder" by means of predicate "wf", use rule wf_wellorderI.
INCOMPATIBILITY.

* Theory Orderings: added class "preorder" as superclass of "order".
INCOMPATIBILITY: Instantiation proofs for order, linorder
etc. slightly changed.  Some theorems named order_class.* now named
preorder_class.*.

* Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
"diag" to "Id_on".

* Theory Finite_Set: added a new fold combinator of type

  ('a => 'b => 'b) => 'b => 'a set => 'b

Occasionally this is more convenient than the old fold combinator
which is now defined in terms of the new one and renamed to
fold_image.

* Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
and "ring_simps" have been replaced by "algebra_simps" (which can be
extended with further lemmas!).  At the moment both still exist but
the former will disappear at some point.

* Theory Power: Lemma power_Suc is now declared as a simp rule in
class recpower.  Type-specific simp rules for various recpower types
have been removed.  INCOMPATIBILITY, rename old lemmas as follows:

rat_power_0    -> power_0
rat_power_Suc  -> power_Suc
realpow_0      -> power_0
realpow_Suc    -> power_Suc
complexpow_0   -> power_0
complexpow_Suc -> power_Suc
power_poly_0   -> power_0
power_poly_Suc -> power_Suc

* Theories Ring_and_Field and Divides: Definition of "op dvd" has been
moved to separate class dvd in Ring_and_Field; a couple of lemmas on
dvd has been generalized to class comm_semiring_1.  Likewise a bunch
of lemmas from Divides has been generalized from nat to class
semiring_div.  INCOMPATIBILITY.  This involves the following theorem
renames resulting from duplicate elimination:

    dvd_def_mod ~>          dvd_eq_mod_eq_0
    zero_dvd_iff ~>         dvd_0_left_iff
    dvd_0 ~>                dvd_0_right
    DIVISION_BY_ZERO_DIV ~> div_by_0
    DIVISION_BY_ZERO_MOD ~> mod_by_0
    mult_div ~>             div_mult_self2_is_id
    mult_mod ~>             mod_mult_self2_is_0

* Theory IntDiv: removed many lemmas that are instances of class-based
generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
rename old lemmas as follows:

dvd_diff               -> nat_dvd_diff
dvd_zminus_iff         -> dvd_minus_iff
mod_add1_eq            -> mod_add_eq
mod_mult1_eq           -> mod_mult_right_eq
mod_mult1_eq'          -> mod_mult_left_eq
mod_mult_distrib_mod   -> mod_mult_eq
nat_mod_add_left_eq    -> mod_add_left_eq
nat_mod_add_right_eq   -> mod_add_right_eq
nat_mod_div_trivial    -> mod_div_trivial
nat_mod_mod_trivial    -> mod_mod_trivial
zdiv_zadd_self1        -> div_add_self1
zdiv_zadd_self2        -> div_add_self2
zdiv_zmult_self1       -> div_mult_self2_is_id
zdiv_zmult_self2       -> div_mult_self1_is_id
zdvd_triv_left         -> dvd_triv_left
zdvd_triv_right        -> dvd_triv_right
zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
zmod_zadd_left_eq      -> mod_add_left_eq
zmod_zadd_right_eq     -> mod_add_right_eq
zmod_zadd_self1        -> mod_add_self1
zmod_zadd_self2        -> mod_add_self2
zmod_zadd1_eq          -> mod_add_eq
zmod_zdiff1_eq         -> mod_diff_eq
zmod_zdvd_zmod         -> mod_mod_cancel
zmod_zmod_cancel       -> mod_mod_cancel
zmod_zmult_self1       -> mod_mult_self2_is_0
zmod_zmult_self2       -> mod_mult_self1_is_0
zmod_1                 -> mod_by_1
zdiv_1                 -> div_by_1
zdvd_abs1              -> abs_dvd_iff
zdvd_abs2              -> dvd_abs_iff
zdvd_refl              -> dvd_refl
zdvd_trans             -> dvd_trans
zdvd_zadd              -> dvd_add
zdvd_zdiff             -> dvd_diff
zdvd_zminus_iff        -> dvd_minus_iff
zdvd_zminus2_iff       -> minus_dvd_iff
zdvd_zmultD            -> dvd_mult_right
zdvd_zmultD2           -> dvd_mult_left
zdvd_zmult_mono        -> mult_dvd_mono
zdvd_0_right           -> dvd_0_right
zdvd_0_left            -> dvd_0_left_iff
zdvd_1_left            -> one_dvd
zminus_dvd_iff         -> minus_dvd_iff

* Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.

* The real numbers offer decimal input syntax: 12.34 is translated
into 1234/10^2. This translation is not reversed upon output.

* Theory Library/Polynomial defines an abstract type 'a poly of
univariate polynomials with coefficients of type 'a.  In addition to
the standard ring operations, it also supports div and mod.  Code
generation is also supported, using list-style constructors.

* Theory Library/Inner_Product defines a class of real_inner for real
inner product spaces, with an overloaded operation inner :: 'a => 'a
=> real.  Class real_inner is a subclass of real_normed_vector from
theory RealVector.

* Theory Library/Product_Vector provides instances for the product
type 'a * 'b of several classes from RealVector and Inner_Product.
Definitions of addition, subtraction, scalar multiplication, norms,
and inner products are included.

* Theory Library/Bit defines the field "bit" of integers modulo 2.  In
addition to the field operations, numerals and case syntax are also
supported.

* Theory Library/Diagonalize provides constructive version of Cantor's
first diagonalization argument.

* Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
zlcm (for int); carried together from various gcd/lcm developements in
the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
may recover tupled syntax as follows:

    hide (open) const gcd
    abbreviation gcd where
      "gcd == (%(a, b). GCD.gcd a b)"
    notation (output)
      GCD.gcd ("gcd '(_, _')")

The same works for lcm, zgcd, zlcm.

* Theory Library/Nat_Infinity: added addition, numeral syntax and more
instantiations for algebraic structures.  Removed some duplicate
theorems.  Changes in simp rules.  INCOMPATIBILITY.

* ML antiquotation @{code} takes a constant as argument and generates
corresponding code in background and inserts name of the corresponding
resulting ML value/function/datatype constructor binding in place.
All occurrences of @{code} with a single ML block are generated
simultaneously.  Provides a generic and safe interface for
instrumentalizing code generation.  See
src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
In future you ought to refrain from ad-hoc compiling generated SML
code on the ML toplevel.  Note that (for technical reasons) @{code}
cannot refer to constants for which user-defined serializations are
set.  Refer to the corresponding ML counterpart directly in that
cases.

* Command 'rep_datatype': instead of theorem names the command now
takes a list of terms denoting the constructors of the type to be
represented as datatype.  The characteristic theorems have to be
proven.  INCOMPATIBILITY.  Also observe that the following theorems
have disappeared in favour of existing ones:

    unit_induct                 ~> unit.induct
    prod_induct                 ~> prod.induct
    sum_induct                  ~> sum.induct
    Suc_Suc_eq                  ~> nat.inject
    Suc_not_Zero Zero_not_Suc   ~> nat.distinct


*** HOL-Algebra ***

* New locales for orders and lattices where the equivalence relation
is not restricted to equality.  INCOMPATIBILITY: all order and lattice
locales use a record structure with field eq for the equivalence.

* New theory of factorial domains.

* Units_l_inv and Units_r_inv are now simp rules by default.
INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
and/or r_inv will now also require deletion of these lemmas.

* Renamed the following theorems, INCOMPATIBILITY:

UpperD ~> Upper_memD
LowerD ~> Lower_memD
least_carrier ~> least_closed
greatest_carrier ~> greatest_closed
greatest_Lower_above ~> greatest_Lower_below
one_zero ~> carrier_one_zero
one_not_zero ~> carrier_one_not_zero  (collision with assumption)


*** HOL-Nominal ***

* Nominal datatypes can now contain type-variables.

* Commands 'nominal_inductive' and 'equivariance' work with local
theory targets.

* Nominal primrec can now works with local theory targets and its
specification syntax now conforms to the general format as seen in
'inductive' etc.

* Method "perm_simp" honours the standard simplifier attributes
(no_asm), (no_asm_use) etc.

* The new predicate #* is defined like freshness, except that on the
left hand side can be a set or list of atoms.

* Experimental command 'nominal_inductive2' derives strong induction
principles for inductive definitions.  In contrast to
'nominal_inductive', which can only deal with a fixed number of
binders, it can deal with arbitrary expressions standing for sets of
atoms to be avoided.  The only inductive definition we have at the
moment that needs this generalisation is the typing rule for Lets in
the algorithm W:

 Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
 -----------------------------------------------------------------
         Gamma |- Let x be t1 in t2 : T2

In this rule one wants to avoid all the binders that are introduced by
"close Gamma T1".  We are looking for other examples where this
feature might be useful.  Please let us know.


*** HOLCF ***

* Reimplemented the simplification procedure for proving continuity
subgoals.  The new simproc is extensible; users can declare additional
continuity introduction rules with the attribute [cont2cont].

* The continuity simproc now uses a different introduction rule for
solving continuity subgoals on terms with lambda abstractions.  In
some rare cases the new simproc may fail to solve subgoals that the
old one could solve, and "simp add: cont2cont_LAM" may be necessary.
Potential INCOMPATIBILITY.

* Command 'fixrec': specification syntax now conforms to the general
format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
examples.  INCOMPATIBILITY.


*** ZF ***

* Proof of Zorn's Lemma for partial orders.


*** ML ***

* Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
depends on multithreading, so timouts will not work before Poly/ML
5.2.1!

* High-level support for concurrent ML programming, see
src/Pure/Cuncurrent.  The data-oriented model of "future values" is
particularly convenient to organize independent functional
computations.  The concept of "synchronized variables" provides a
higher-order interface for components with shared state, avoiding the
delicate details of mutexes and condition variables.  (Requires
Poly/ML 5.2.1 or later.)

* ML bindings produced via Isar commands are stored within the Isar
context (theory or proof).  Consequently, commands like 'use' and 'ML'
become thread-safe and work with undo as expected (concerning
top-level bindings, not side-effects on global references).
INCOMPATIBILITY, need to provide proper Isar context when invoking the
compiler at runtime; really global bindings need to be given outside a
theory.  (Requires Poly/ML 5.2 or later.)

* Command 'ML_prf' is analogous to 'ML' but works within a proof
context.  Top-level ML bindings are stored within the proof context in
a purely sequential fashion, disregarding the nested proof structure.
ML bindings introduced by 'ML_prf' are discarded at the end of the
proof.  (Requires Poly/ML 5.2 or later.)

* Simplified ML attribute and method setup, cf. functions Attrib.setup
and Method.setup, as well as Isar commands 'attribute_setup' and
'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
existing code accordingly, or use plain 'setup' together with old
Method.add_method.

* Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
to 'a -> thm, while results are always tagged with an authentic oracle
name.  The Isar command 'oracle' is now polymorphic, no argument type
is specified.  INCOMPATIBILITY, need to simplify existing oracle code
accordingly.  Note that extra performance may be gained by producing
the cterm carefully, avoiding slow Thm.cterm_of.

* Simplified interface for defining document antiquotations via
ThyOutput.antiquotation, ThyOutput.output, and optionally
ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
examples.

* More systematic treatment of long names, abstract name bindings, and
name space operations.  Basic operations on qualified names have been
move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
Long_Name.append.  Old type bstring has been mostly replaced by
abstract type binding (see structure Binding), which supports precise
qualification by packages and local theory targets, as well as proper
tracking of source positions.  INCOMPATIBILITY, need to wrap old
bstring values into Binding.name, or better pass through abstract
bindings everywhere.  See further src/Pure/General/long_name.ML,
src/Pure/General/binding.ML and src/Pure/General/name_space.ML

* Result facts (from PureThy.note_thms, ProofContext.note_thms,
LocalTheory.note etc.) now refer to the *full* internal name, not the
bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!

* Disposed old type and term read functions (Sign.read_def_typ,
Sign.read_typ, Sign.read_def_terms, Sign.read_term,
Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
Syntax.read_term_global etc.; see also OldGoals.read_term as last
resort for legacy applications.

* Disposed old declarations, tactics, tactic combinators that refer to
the simpset or claset of an implicit theory (such as Addsimps,
Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
embedded ML text, or local_simpset_of with a proper context passed as
explicit runtime argument.

* Rules and tactics that read instantiations (read_instantiate,
res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
context, which is required for parsing and type-checking.  Moreover,
the variables are specified as plain indexnames, not string encodings
thereof.  INCOMPATIBILITY.

* Generic Toplevel.add_hook interface allows to analyze the result of
transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
for theorem dependency output of transactions resulting in a new
theory state.

* ML antiquotations: block-structured compilation context indicated by
\<lbrace> ... \<rbrace>; additional antiquotation forms:

  @{binding name}                         - basic name binding
  @{let ?pat = term}                      - term abbreviation (HO matching)
  @{note name = fact}                     - fact abbreviation
  @{thm fact}                             - singleton fact (with attributes)
  @{thms fact}                            - general fact (with attributes)
  @{lemma prop by method}                 - singleton goal
  @{lemma prop by meth1 meth2}            - singleton goal
  @{lemma prop1 ... propN by method}      - general goal
  @{lemma prop1 ... propN by meth1 meth2} - general goal
  @{lemma (open) ...}                     - open derivation


*** System ***

* The Isabelle "emacs" tool provides a specific interface to invoke
Proof General / Emacs, with more explicit failure if that is not
installed (the old isabelle-interface script silently falls back on
isabelle-process).  The PROOFGENERAL_HOME setting determines the
installation location of the Proof General distribution.

* Isabelle/lib/classes/Pure.jar provides basic support to integrate
the Isabelle process into a JVM/Scala application.  See
Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
process wrapper has been discontinued.)

* Added homegrown Isabelle font with unicode layout, see lib/fonts.

* Various status messages (with exact source position information) are
emitted, if proper markup print mode is enabled.  This allows
user-interface components to provide detailed feedback on internal
prover operations.



New in Isabelle2008 (June 2008)
-------------------------------

*** General ***

* The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
and updated, with formally checked references as hyperlinks.

* Theory loader: use_thy (and similar operations) no longer set the
implicit ML context, which was occasionally hard to predict and in
conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
provides a proper context already.

* Theory loader: old-style ML proof scripts being *attached* to a thy
file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
'use' within a theory file will do the job.

* Name space merge now observes canonical order, i.e. the second space
is inserted into the first one, while existing entries in the first
space take precedence.  INCOMPATIBILITY in rare situations, may try to
swap theory imports.

* Syntax: symbol \<chi> is now considered a letter.  Potential
INCOMPATIBILITY in identifier syntax etc.

* Outer syntax: string tokens no longer admit escaped white space,
which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
white space without escapes.

* Outer syntax: string tokens may contain arbitrary character codes
specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
"foo_bar".


*** Pure ***

* Context-dependent token translations.  Default setup reverts locally
fixed variables, and adds hilite markup for undeclared frees.

* Unused theorems can be found using the new command 'unused_thms'.
There are three ways of invoking it:

(1) unused_thms
     Only finds unused theorems in the current theory.

(2) unused_thms thy_1 ... thy_n -
     Finds unused theorems in the current theory and all of its ancestors,
     excluding the theories thy_1 ... thy_n and all of their ancestors.

(3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
     Finds unused theorems in the theories thy'_1 ... thy'_m and all of
     their ancestors, excluding the theories thy_1 ... thy_n and all of
     their ancestors.

In order to increase the readability of the list produced by
unused_thms, theorems that have been created by a particular instance
of a theory command such as 'inductive' or 'function' are considered
to belong to the same "group", meaning that if at least one theorem in
this group is used, the other theorems in the same group are no longer
reported as unused.  Moreover, if all theorems in the group are
unused, only one theorem in the group is displayed.

Note that proof objects have to be switched on in order for
unused_thms to work properly (i.e. !proofs must be >= 1, which is
usually the case when using Proof General with the default settings).

* Authentic naming of facts disallows ad-hoc overwriting of previous
theorems within the same name space.  INCOMPATIBILITY, need to remove
duplicate fact bindings, or even accidental fact duplications.  Note
that tools may maintain dynamically scoped facts systematically, using
PureThy.add_thms_dynamic.

* Command 'hide' now allows to hide from "fact" name space as well.

* Eliminated destructive theorem database, simpset, claset, and
clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
update of theories within ML code.

* Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
INCOMPATIBILITY, object-logics depending on former Pure require
additional setup PureThy.old_appl_syntax_setup; object-logics
depending on former CPure need to refer to Pure.

* Commands 'use' and 'ML' are now purely functional, operating on
theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
INCOMPATIBILITY.

* Command 'setup': discontinued implicit version with ML reference.

* Instantiation target allows for simultaneous specification of class
instance operations together with an instantiation proof.
Type-checking phase allows to refer to class operations uniformly.
See src/HOL/Complex/Complex.thy for an Isar example and
src/HOL/Library/Eval.thy for an ML example.

* Indexing of literal facts: be more serious about including only
facts from the visible specification/proof context, but not the
background context (locale etc.).  Affects `prop` notation and method
"fact".  INCOMPATIBILITY: need to name facts explicitly in rare
situations.

* Method "cases", "induct", "coinduct": removed obsolete/undocumented
"(open)" option, which used to expose internal bound variables to the
proof text.

* Isar statements: removed obsolete case "rule_context".
INCOMPATIBILITY, better use explicit fixes/assumes.

* Locale proofs: default proof step now includes 'unfold_locales';
hence 'proof' without argument may be used to unfold locale
predicates.


*** Document preparation ***

* Simplified pdfsetup.sty: color/hyperref is used unconditionally for
both pdf and dvi (hyperlinks usually work in xdvi as well); removed
obsolete thumbpdf setup (contemporary PDF viewers do this on the
spot); renamed link color from "darkblue" to "linkcolor" (default
value unchanged, can be redefined via \definecolor); no longer sets
"a4paper" option (unnecessary or even intrusive).

* Antiquotation @{lemma A method} proves proposition A by the given
method (either a method name or a method name plus (optional) method
arguments in parentheses) and prints A just like @{prop A}.


*** HOL ***

* New primrec package.  Specification syntax conforms in style to
definition/function/....  No separate induction rule is provided.  The
"primrec" command distinguishes old-style and new-style specifications
by syntax.  The former primrec package is now named OldPrimrecPackage.
When adjusting theories, beware: constants stemming from new-style
primrec specifications have authentic syntax.

* Metis prover is now an order of magnitude faster, and also works
with multithreading.

* Metis: the maximum number of clauses that can be produced from a
theorem is now given by the attribute max_clauses.  Theorems that
exceed this number are ignored, with a warning printed.

* Sledgehammer no longer produces structured proofs by default. To
enable, declare [[sledgehammer_full = true]].  Attributes
reconstruction_modulus, reconstruction_sorts renamed
sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.

* Method "induct_scheme" derives user-specified induction rules
from well-founded induction and completeness of patterns. This factors
out some operations that are done internally by the function package
and makes them available separately.  See
src/HOL/ex/Induction_Scheme.thy for examples.

* More flexible generation of measure functions for termination
proofs: Measure functions can be declared by proving a rule of the
form "is_measure f" and giving it the [measure_function] attribute.
The "is_measure" predicate is logically meaningless (always true), and
just guides the heuristic.  To find suitable measure functions, the
termination prover sets up the goal "is_measure ?f" of the appropriate
type and generates all solutions by prolog-style backwards proof using
the declared rules.

This setup also deals with rules like 

  "is_measure f ==> is_measure (list_size f)"

which accommodates nested datatypes that recurse through lists.
Similar rules are predeclared for products and option types.

* Turned the type of sets "'a set" into an abbreviation for "'a => bool"

  INCOMPATIBILITIES:

  - Definitions of overloaded constants on sets have to be replaced by
    definitions on => and bool.

  - Some definitions of overloaded operators on sets can now be proved
    using the definitions of the operators on => and bool.  Therefore,
    the following theorems have been renamed:

      subset_def   -> subset_eq
      psubset_def  -> psubset_eq
      set_diff_def -> set_diff_eq
      Compl_def    -> Compl_eq
      Sup_set_def  -> Sup_set_eq
      Inf_set_def  -> Inf_set_eq
      sup_set_def  -> sup_set_eq
      inf_set_def  -> inf_set_eq

  - Due to the incompleteness of the HO unification algorithm, some
    rules such as subst may require manual instantiation, if some of
    the unknowns in the rule is a set.

  - Higher order unification and forward proofs:
    The proof pattern

      have "P (S::'a set)" <...>
      then have "EX S. P S" ..

    no longer works (due to the incompleteness of the HO unification
    algorithm) and must be replaced by the pattern

      have "EX S. P S"
      proof
        show "P S" <...>
      qed

  - Calculational reasoning with subst (or similar rules):
    The proof pattern

      have "P (S::'a set)" <...>
      also have "S = T" <...>
      finally have "P T" .

    no longer works (for similar reasons as the previous example) and
    must be replaced by something like

      have "P (S::'a set)" <...>
      moreover have "S = T" <...>
      ultimately have "P T" by simp

  - Tactics or packages written in ML code:
    Code performing pattern matching on types via

      Type ("set", [T]) => ...

    must be rewritten. Moreover, functions like strip_type or
    binder_types no longer return the right value when applied to a
    type of the form

      T1 => ... => Tn => U => bool

    rather than

      T1 => ... => Tn => U set

* Merged theories Wellfounded_Recursion, Accessible_Part and
Wellfounded_Relations to theory Wellfounded.

* Explicit class "eq" for executable equality.  INCOMPATIBILITY.

* Class finite no longer treats UNIV as class parameter.  Use class
enum from theory Library/Enum instead to achieve a similar effect.
INCOMPATIBILITY.

* Theory List: rule list_induct2 now has explicitly named cases "Nil"
and "Cons".  INCOMPATIBILITY.

* HOL (and FOL): renamed variables in rules imp_elim and swap.
Potential INCOMPATIBILITY.

* Theory Product_Type: duplicated lemmas split_Pair_apply and
injective_fst_snd removed, use split_eta and prod_eqI instead.
Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.

* Theory Nat: removed redundant lemmas that merely duplicate lemmas of
the same name in theory Orderings:

  less_trans
  less_linear
  le_imp_less_or_eq
  le_less_trans
  less_le_trans
  less_not_sym
  less_asym

Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
and different variable names.

* Library/Option_ord.thy: Canonical order on option type.

* Library/RBT.thy: Red-black trees, an efficient implementation of
finite maps.

* Library/Countable.thy: Type class for countable types.

* Theory Int: The representation of numerals has changed.  The infix
operator BIT and the bit datatype with constructors B0 and B1 have
disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
accordingly.

* Theory Nat: definition of <= and < on natural numbers no longer
depend on well-founded relations.  INCOMPATIBILITY.  Definitions
le_def and less_def have disappeared.  Consider lemmas not_less
[symmetric, where ?'a = nat] and less_eq [symmetric] instead.

* Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
(whose purpose mainly is for various fold_set functionals) have been
abandoned in favor of the existing algebraic classes
ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
lower_semilattice (resp. upper_semilattice) and linorder.
INCOMPATIBILITY.

* Theory Transitive_Closure: induct and cases rules now declare proper
case_names ("base" and "step").  INCOMPATIBILITY.

* Theorem Inductive.lfp_ordinal_induct generalized to complete
lattices.  The form set-specific version is available as
Inductive.lfp_ordinal_induct_set.

* Renamed theorems "power.simps" to "power_int.simps".
INCOMPATIBILITY.

* Class semiring_div provides basic abstract properties of semirings
with division and modulo operations.  Subsumes former class dvd_mod.

* Merged theories IntDef, Numeral and IntArith into unified theory
Int.  INCOMPATIBILITY.

* Theory Library/Code_Index: type "index" now represents natural
numbers rather than integers.  INCOMPATIBILITY.

* New class "uminus" with operation "uminus" (split of from class
"minus" which now only has operation "minus", binary).
INCOMPATIBILITY.

* Constants "card", "internal_split", "option_map" now with authentic
syntax.  INCOMPATIBILITY.

* Definitions subset_def, psubset_def, set_diff_def, Compl_def,
le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
Sup_set_def, le_def, less_def, option_map_def now with object
equality.  INCOMPATIBILITY.

* Records. Removed K_record, and replaced it by pure lambda term
%x. c. The simplifier setup is now more robust against eta expansion.
INCOMPATIBILITY: in cases explicitly referring to K_record.

* Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.

* Library/ListVector: new theory of arithmetic vector operations.

* Library/Order_Relation: new theory of various orderings as sets of
pairs.  Defines preorders, partial orders, linear orders and
well-orders on sets and on types.


*** ZF ***

* Renamed some theories to allow to loading both ZF and HOL in the
same session:

  Datatype  -> Datatype_ZF
  Inductive -> Inductive_ZF
  Int       -> Int_ZF
  IntDiv    -> IntDiv_ZF
  Nat       -> Nat_ZF
  List      -> List_ZF
  Main      -> Main_ZF

INCOMPATIBILITY: ZF theories that import individual theories below
Main might need to be adapted.  Regular theory Main is still
available, as trivial extension of Main_ZF.


*** ML ***

* ML within Isar: antiquotation @{const name} or @{const
name(typargs)} produces statically-checked Const term.

* Functor NamedThmsFun: data is available to the user as dynamic fact
(of the same name).  Removed obsolete print command.

* Removed obsolete "use_legacy_bindings" function.

* The ``print mode'' is now a thread-local value derived from a global
template (the former print_mode reference), thus access becomes
non-critical.  The global print_mode reference is for session
management only; user-code should use print_mode_value,
print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.

* Functions system/system_out provide a robust way to invoke external
shell commands, with propagation of interrupts (requires Poly/ML
5.2.1).  Do not use OS.Process.system etc. from the basis library!


*** System ***

* Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
in accordance with Proof General 3.7, which prefers GNU emacs.

* isatool tty runs Isabelle process with plain tty interaction;
optional line editor may be specified via ISABELLE_LINE_EDITOR
setting, the default settings attempt to locate "ledit" and "rlwrap".

* isatool browser now works with Cygwin as well, using general
"javapath" function defined in Isabelle process environment.

* YXML notation provides a simple and efficient alternative to
standard XML transfer syntax.  See src/Pure/General/yxml.ML and
isatool yxml as described in the Isabelle system manual.

* JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
provides general wrapper for managing an Isabelle process in a robust
fashion, with ``cooked'' output from stdin/stderr.

* Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).

* Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
way of changing the user's settings is via
ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
script.

* Multithreading.max_threads := 0 refers to the number of actual CPU
cores of the underlying machine, which is a good starting point for
optimal performance tuning.  The corresponding usedir option -M allows
"max" as an alias for "0".  WARNING: does not work on certain versions
of Mac OS (with Poly/ML 5.1).

* isabelle-process: non-ML sessions are run with "nice", to reduce the
adverse effect of Isabelle flooding interactive front-ends (notably
ProofGeneral / XEmacs).



New in Isabelle2007 (November 2007)
-----------------------------------

*** General ***

* More uniform information about legacy features, notably a
warning/error of "Legacy feature: ...", depending on the state of the
tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
legacy features will disappear eventually.

* Theory syntax: the header format ``theory A = B + C:'' has been
discontinued in favour of ``theory A imports B C begin''.  Use isatool
fixheaders to convert existing theory files.  INCOMPATIBILITY.

* Theory syntax: the old non-Isar theory file format has been
discontinued altogether.  Note that ML proof scripts may still be used
with Isar theories; migration is usually quite simple with the ML
function use_legacy_bindings.  INCOMPATIBILITY.

* Theory syntax: some popular names (e.g. 'class', 'declaration',
'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
quotes.

* Theory loader: be more serious about observing the static theory
header specifications (including optional directories), but not the
accidental file locations of previously successful loads.  The strict
update policy of former update_thy is now already performed by
use_thy, so the former has been removed; use_thys updates several
theories simultaneously, just as 'imports' within a theory header
specification, but without merging the results.  Potential
INCOMPATIBILITY: may need to refine theory headers and commands
ROOT.ML which depend on load order.

* Theory loader: optional support for content-based file
identification, instead of the traditional scheme of full physical
path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
(cf. the system manual).  The new scheme allows to work with
non-finished theories in persistent session images, such that source
files may be moved later on without requiring reloads.

* Theory loader: old-style ML proof scripts being *attached* to a thy
file (with the same base name as the theory) are considered a legacy
feature, which will disappear eventually. Even now, the theory loader
no longer maintains dependencies on such files.

* Syntax: the scope for resolving ambiguities via type-inference is
now limited to individual terms, instead of whole simultaneous
specifications as before. This greatly reduces the complexity of the
syntax module and improves flexibility by separating parsing and
type-checking. INCOMPATIBILITY: additional type-constraints (explicit
'fixes' etc.) are required in rare situations.

* Syntax: constants introduced by new-style packages ('definition',
'abbreviation' etc.) are passed through the syntax module in
``authentic mode''. This means that associated mixfix annotations
really stick to such constants, independently of potential name space
ambiguities introduced later on. INCOMPATIBILITY: constants in parse
trees are represented slightly differently, may need to adapt syntax
translations accordingly. Use CONST marker in 'translations' and
@{const_syntax} antiquotation in 'parse_translation' etc.

* Legacy goal package: reduced interface to the bare minimum required
to keep existing proof scripts running.  Most other user-level
functions are now part of the OldGoals structure, which is *not* open
by default (consider isatool expandshort before open OldGoals).
Removed top_sg, prin, printyp, pprint_term/typ altogether, because
these tend to cause confusion about the actual goal (!) context being
used here, which is not necessarily the same as the_context().

* Command 'find_theorems': supports "*" wild-card in "name:"
criterion; "with_dups" option.  Certain ProofGeneral versions might
support a specific search form (see ProofGeneral/CHANGES).

* The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
by default, which means that "prems" (and also "fixed variables") are
suppressed from proof state output.  Note that the ProofGeneral
settings mechanism allows to change and save options persistently, but
older versions of Isabelle will fail to start up if a negative prems
limit is imposed.

* Local theory targets may be specified by non-nested blocks of
``context/locale/class ... begin'' followed by ``end''.  The body may
contain definitions, theorems etc., including any derived mechanism
that has been implemented on top of these primitives.  This concept
generalizes the existing ``theorem (in ...)'' towards more versatility
and scalability.

* Proof General interface: proper undo of final 'end' command;
discontinued Isabelle/classic mode (ML proof scripts).


*** Document preparation ***

* Added antiquotation @{theory name} which prints the given name,
after checking that it refers to a valid ancestor theory in the
current context.

* Added antiquotations @{ML_type text} and @{ML_struct text} which
check the given source text as ML type/structure, printing verbatim.

* Added antiquotation @{abbrev "c args"} which prints the abbreviation
"c args == rhs" given in the current context.  (Any number of
arguments may be given on the LHS.)


*** Pure ***

* The 'class' package offers a combination of axclass and locale to
achieve Haskell-like type classes in Isabelle.  Definitions and
theorems within a class context produce both relative results (with
implicit parameters according to the locale context), and polymorphic
constants with qualified polymorphism (according to the class
context).  Within the body context of a 'class' target, a separate
syntax layer ("user space type system") takes care of converting
between global polymorphic consts and internal locale representation.
See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
"isatool doc classes" provides a tutorial.

* Generic code generator framework allows to generate executable
code for ML and Haskell (including Isabelle classes).  A short usage
sketch:

    internal compilation:
        export_code <list of constants (term syntax)> in SML
    writing SML code to a file:
        export_code <list of constants (term syntax)> in SML <filename>
    writing OCaml code to a file:
        export_code <list of constants (term syntax)> in OCaml <filename>
    writing Haskell code to a bunch of files:
        export_code <list of constants (term syntax)> in Haskell <filename>

    evaluating closed propositions to True/False using code generation:
        method ``eval''

Reasonable default setup of framework in HOL.

Theorem attributs for selecting and transforming function equations theorems:

    [code fun]:        select a theorem as function equation for a specific constant
    [code fun del]:    deselect a theorem as function equation for a specific constant
    [code inline]:     select an equation theorem for unfolding (inlining) in place
    [code inline del]: deselect an equation theorem for unfolding (inlining) in place

User-defined serializations (target in {SML, OCaml, Haskell}):

    code_const <and-list of constants (term syntax)>
      {(target) <and-list of const target syntax>}+

    code_type <and-list of type constructors>
      {(target) <and-list of type target syntax>}+

    code_instance <and-list of instances>
      {(target)}+
        where instance ::= <type constructor> :: <class>

    code_class <and_list of classes>
      {(target) <and-list of class target syntax>}+
        where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?

code_instance and code_class only are effective to target Haskell.

For example usage see src/HOL/ex/Codegenerator.thy and
src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
generation from Isabelle/HOL theories is available via "isatool doc
codegen".

* Code generator: consts in 'consts_code' Isar commands are now
referred to by usual term syntax (including optional type
annotations).

* Command 'no_translations' removes translation rules from theory
syntax.

* Overloaded definitions are now actually checked for acyclic
dependencies.  The overloading scheme is slightly more general than
that of Haskell98, although Isabelle does not demand an exact
correspondence to type class and instance declarations.
INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
exotic versions of overloading -- at the discretion of the user!

Polymorphic constants are represented via type arguments, i.e. the
instantiation that matches an instance against the most general
declaration given in the signature.  For example, with the declaration
c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
as c(nat).  Overloading is essentially simultaneous structural
recursion over such type arguments.  Incomplete specification patterns
impose global constraints on all occurrences, e.g. c('a * 'a) on the
LHS means that more general c('a * 'b) will be disallowed on any RHS.
Command 'print_theory' outputs the normalized system of recursive
equations, see section "definitions".

* Configuration options are maintained within the theory or proof
context (with name and type bool/int/string), providing a very simple
interface to a poor-man's version of general context data.  Tools may
declare options in ML (e.g. using Attrib.config_int) and then refer to
these values using Config.get etc.  Users may change options via an
associated attribute of the same name.  This form of context
declaration works particularly well with commands 'declare' or
'using', for example ``declare [[foo = 42]]''.  Thus it has become
very easy to avoid global references, which would not observe Isar
toplevel undo/redo and fail to work with multithreading.

Various global ML references of Pure and HOL have been turned into
configuration options:

  Unify.search_bound		unify_search_bound
  Unify.trace_bound		unify_trace_bound
  Unify.trace_simp		unify_trace_simp
  Unify.trace_types		unify_trace_types
  Simplifier.simp_depth_limit	simp_depth_limit
  Blast.depth_limit		blast_depth_limit
  DatatypeProp.dtK		datatype_distinctness_limit
  fast_arith_neq_limit  	fast_arith_neq_limit
  fast_arith_split_limit	fast_arith_split_limit

* Named collections of theorems may be easily installed as context
data using the functor NamedThmsFun (see also
src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
attributes; there is also a toplevel print command.  This facility is
just a common case of general context data, which is the preferred way
for anything more complex than just a list of facts in canonical
order.

* Isar: command 'declaration' augments a local theory by generic
declaration functions written in ML.  This enables arbitrary content
being added to the context, depending on a morphism that tells the
difference of the original declaration context wrt. the application
context encountered later on.

* Isar: proper interfaces for simplification procedures.  Command
'simproc_setup' declares named simprocs (with match patterns, and body
text in ML).  Attribute "simproc" adds/deletes simprocs in the current
context.  ML antiquotation @{simproc name} retrieves named simprocs.

* Isar: an extra pair of brackets around attribute declarations
abbreviates a theorem reference involving an internal dummy fact,
which will be ignored later --- only the effect of the attribute on
the background context will persist.  This form of in-place
declarations is particularly useful with commands like 'declare' and
'using', for example ``have A using [[simproc a]] by simp''.

* Isar: method "assumption" (and implicit closing of subproofs) now
takes simple non-atomic goal assumptions into account: after applying
an assumption as a rule the resulting subgoals are solved by atomic
assumption steps.  This is particularly useful to finish 'obtain'
goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
without referring to the original premise "!!x. P x ==> thesis" in the
Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
more permissive.

* Isar: implicit use of prems from the Isar proof context is
considered a legacy feature.  Common applications like ``have A .''
may be replaced by ``have A by fact'' or ``note `A`''.  In general,
referencing facts explicitly here improves readability and
maintainability of proof texts.

* Isar: improper proof element 'guess' is like 'obtain', but derives
the obtained context from the course of reasoning!  For example:

  assume "EX x y. A x & B y"   -- "any previous fact"
  then guess x and y by clarify

This technique is potentially adventurous, depending on the facts and
proof tools being involved here.

* Isar: known facts from the proof context may be specified as literal
propositions, using ASCII back-quote syntax.  This works wherever
named facts used to be allowed so far, in proof commands, proof
methods, attributes etc.  Literal facts are retrieved from the context
according to unification of type and term parameters.  For example,
provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
theorems in the current context, then these are valid literal facts:
`A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.

There is also a proof method "fact" which does the same composition
for explicit goal states, e.g. the following proof texts coincide with
certain special cases of literal facts:

  have "A" by fact                 ==  note `A`
  have "A ==> B" by fact           ==  note `A ==> B`
  have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  have "P a ==> Q a" by fact       ==  note `P a ==> Q a`

* Isar: ":" (colon) is no longer a symbolic identifier character in
outer syntax.  Thus symbolic identifiers may be used without
additional white space in declarations like this: ``assume *: A''.

* Isar: 'print_facts' prints all local facts of the current context,
both named and unnamed ones.

* Isar: 'def' now admits simultaneous definitions, e.g.:

  def x == "t" and y == "u"

* Isar: added command 'unfolding', which is structurally similar to
'using', but affects both the goal state and facts by unfolding given
rewrite rules.  Thus many occurrences of the 'unfold' method or
'unfolded' attribute may be replaced by first-class proof text.

* Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
and command 'unfolding' now all support object-level equalities
(potentially conditional).  The underlying notion of rewrite rule is
analogous to the 'rule_format' attribute, but *not* that of the
Simplifier (which is usually more generous).

* Isar: the new attribute [rotated n] (default n = 1) rotates the
premises of a theorem by n. Useful in conjunction with drule.

* Isar: the goal restriction operator [N] (default N = 1) evaluates a
method expression within a sandbox consisting of the first N
sub-goals, which need to exist.  For example, ``simp_all [3]''
simplifies the first three sub-goals, while (rule foo, simp_all)[]
simplifies all new goals that emerge from applying rule foo to the
originally first one.

* Isar: schematic goals are no longer restricted to higher-order
patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
expected.

* Isar: the conclusion of a long theorem statement is now either
'shows' (a simultaneous conjunction, as before), or 'obtains'
(essentially a disjunction of cases with local parameters and
assumptions).  The latter allows to express general elimination rules
adequately; in this notation common elimination rules look like this:

  lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
    assumes "EX x. P x"
    obtains x where "P x"

  lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
    assumes "A & B"
    obtains A and B

  lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
    assumes "A | B"
    obtains
      A
    | B

The subsequent classical rules even refer to the formal "thesis"
explicitly:

  lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
    obtains "~ thesis"

  lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
    obtains "thesis ==> something"

The actual proof of an 'obtains' statement is analogous to that of the
Isar proof element 'obtain', only that there may be several cases.
Optional case names may be specified in parentheses; these will be
available both in the present proof and as annotations in the
resulting rule, for later use with the 'cases' method (cf. attribute
case_names).

* Isar: the assumptions of a long theorem statement are available as
"assms" fact in the proof context.  This is more appropriate than the
(historical) "prems", which refers to all assumptions of the current
context, including those from the target locale, proof body etc.

* Isar: 'print_statement' prints theorems from the current theory or
proof context in long statement form, according to the syntax of a
top-level lemma.

* Isar: 'obtain' takes an optional case name for the local context
introduction rule (default "that").

* Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
explicit (is "_ ==> ?foo") in the rare cases where this still happens
to occur.

* Pure: syntax "CONST name" produces a fully internalized constant
according to the current context.  This is particularly useful for
syntax translations that should refer to internal constant
representations independently of name spaces.

* Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
instead of "FOO ". This allows multiple binder declarations to coexist
in the same context.  INCOMPATIBILITY.

* Isar/locales: 'notation' provides a robust interface to the 'syntax'
primitive that also works in a locale context (both for constants and
fixed variables). Type declaration and internal syntactic representation
of given constants retrieved from the context. Likewise, the
'no_notation' command allows to remove given syntax annotations from the
current context.

* Isar/locales: new derived specification elements 'axiomatization',
'definition', 'abbreviation', which support type-inference, admit
object-level specifications (equality, equivalence).  See also the
isar-ref manual.  Examples:

  axiomatization
    eq  (infix "===" 50) where
    eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"

  definition "f x y = x + y + 1"
  definition g where "g x = f x x"

  abbreviation
    neq  (infix "=!=" 50) where
    "x =!= y == ~ (x === y)"

These specifications may be also used in a locale context.  Then the
constants being introduced depend on certain fixed parameters, and the
constant name is qualified by the locale base name.  An internal
abbreviation takes care for convenient input and output, making the
parameters implicit and using the original short name.  See also
src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
entities from a monomorphic theory.

Presently, abbreviations are only available 'in' a target locale, but
not inherited by general import expressions.  Also note that
'abbreviation' may be used as a type-safe replacement for 'syntax' +
'translations' in common applications.  The "no_abbrevs" print mode
prevents folding of abbreviations in term output.

Concrete syntax is attached to specified constants in internal form,
independently of name spaces.  The parse tree representation is
slightly different -- use 'notation' instead of raw 'syntax', and
'translations' with explicit "CONST" markup to accommodate this.

* Pure/Isar: unified syntax for new-style specification mechanisms
(e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
full type inference and dummy patterns ("_").  For example:

  definition "K x _ = x"

  inductive conj for A B
  where "A ==> B ==> conj A B"

* Pure: command 'print_abbrevs' prints all constant abbreviations of
the current context.  Print mode "no_abbrevs" prevents inversion of
abbreviations on output.

* Isar/locales: improved parameter handling: use of locales "var" and
"struct" no longer necessary; - parameter renamings are no longer
required to be injective.  For example, this allows to define
endomorphisms as locale endom = homom mult mult h.

* Isar/locales: changed the way locales with predicates are defined.
Instead of accumulating the specification, the imported expression is
now an interpretation.  INCOMPATIBILITY: different normal form of
locale expressions.  In particular, in interpretations of locales with
predicates, goals repesenting already interpreted fragments are not
removed automatically.  Use methods `intro_locales' and
`unfold_locales'; see below.

* Isar/locales: new methods `intro_locales' and `unfold_locales'
provide backward reasoning on locales predicates.  The methods are
aware of interpretations and discharge corresponding goals.
`intro_locales' is less aggressive then `unfold_locales' and does not
unfold predicates to assumptions.

* Isar/locales: the order in which locale fragments are accumulated
has changed.  This enables to override declarations from fragments due
to interpretations -- for example, unwanted simp rules.

* Isar/locales: interpretation in theories and proof contexts has been
extended.  One may now specify (and prove) equations, which are
unfolded in interpreted theorems.  This is useful for replacing
defined concepts (constants depending on locale parameters) by
concepts already existing in the target context.  Example:

  interpretation partial_order ["op <= :: [int, int] => bool"]
    where "partial_order.less (op <=) (x::int) y = (x < y)"

Typically, the constant `partial_order.less' is created by a
definition specification element in the context of locale
partial_order.

* Method "induct": improved internal context management to support
local fixes and defines on-the-fly. Thus explicit meta-level
connectives !!  and ==> are rarely required anymore in inductive goals
(using object-logic connectives for this purpose has been long
obsolete anyway). Common proof patterns are explained in
src/HOL/Induct/Common_Patterns.thy, see also
src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
examples.

* Method "induct": improved handling of simultaneous goals. Instead of
introducing object-level conjunction, the statement is now split into
several conclusions, while the corresponding symbolic cases are nested
accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
see src/HOL/Induct/Common_Patterns.thy, for example.

* Method "induct": mutual induction rules are now specified as a list
of rule sharing the same induction cases. HOL packages usually provide
foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
mutual induction rules differently, i.e. like this:

  (induct rule: foo_bar.inducts)
  (induct set: foo bar)
  (induct pred: foo bar)
  (induct type: foo bar)

The ML function ProjectRule.projections turns old-style rules into the
new format.

* Method "coinduct": dual of induction, see
src/HOL/Library/Coinductive_List.thy for various examples.

* Method "cases", "induct", "coinduct": the ``(open)'' option is
considered a legacy feature.

* Attribute "symmetric" produces result with standardized schematic
variables (index 0).  Potential INCOMPATIBILITY.

* Simplifier: by default the simplifier trace only shows top level
rewrites now. That is, trace_simp_depth_limit is set to 1 by
default. Thus there is less danger of being flooded by the trace. The
trace indicates where parts have been suppressed.
  
* Provers/classical: removed obsolete classical version of elim_format
attribute; classical elim/dest rules are now treated uniformly when
manipulating the claset.

* Provers/classical: stricter checks to ensure that supplied intro,
dest and elim rules are well-formed; dest and elim rules must have at
least one premise.

* Provers/classical: attributes dest/elim/intro take an optional
weight argument for the rule (just as the Pure versions).  Weights are
ignored by automated tools, but determine the search order of single
rule steps.

* Syntax: input syntax now supports dummy variable binding "%_. b",
where the body does not mention the bound variable.  Note that dummy
patterns implicitly depend on their context of bounds, which makes
"{_. _}" match any set comprehension as expected.  Potential
INCOMPATIBILITY -- parse translations need to cope with syntactic
constant "_idtdummy" in the binding position.

* Syntax: removed obsolete syntactic constant "_K" and its associated
parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
for example "A -> B" => "Pi A (%_. B)".

* Pure: 'class_deps' command visualizes the subclass relation, using
the graph browser tool.

* Pure: 'print_theory' now suppresses certain internal declarations by
default; use '!' option for full details.


*** HOL ***

* Method "metis" proves goals by applying the Metis general-purpose
resolution prover (see also http://gilith.com/software/metis/).
Examples are in the directory MetisExamples.  WARNING: the
Isabelle/HOL-Metis integration does not yet work properly with
multi-threading.
  
* Command 'sledgehammer' invokes external automatic theorem provers as
background processes.  It generates calls to the "metis" method if
successful. These can be pasted into the proof.  Users do not have to
wait for the automatic provers to return.  WARNING: does not really
work with multi-threading.

* New "auto_quickcheck" feature tests outermost goal statements for
potential counter-examples.  Controlled by ML references
auto_quickcheck (default true) and auto_quickcheck_time_limit (default
5000 milliseconds).  Fails silently if statements is outside of
executable fragment, or any other codgenerator problem occurs.

* New constant "undefined" with axiom "undefined x = undefined".

* Added class "HOL.eq", allowing for code generation with polymorphic
equality.

* Some renaming of class constants due to canonical name prefixing in
the new 'class' package:

    HOL.abs ~> HOL.abs_class.abs
    HOL.divide ~> HOL.divide_class.divide
    0 ~> HOL.zero_class.zero
    1 ~> HOL.one_class.one
    op + ~> HOL.plus_class.plus
    op - ~> HOL.minus_class.minus
    uminus ~> HOL.minus_class.uminus
    op * ~> HOL.times_class.times
    op < ~> HOL.ord_class.less
    op <= > HOL.ord_class.less_eq
    Nat.power ~> Power.power_class.power
    Nat.size ~> Nat.size_class.size
    Numeral.number_of ~> Numeral.number_class.number_of
    FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
    FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
    Orderings.min ~> Orderings.ord_class.min
    Orderings.max ~> Orderings.ord_class.max
    Divides.op div ~> Divides.div_class.div
    Divides.op mod ~> Divides.div_class.mod
    Divides.op dvd ~> Divides.div_class.dvd

INCOMPATIBILITY.  Adaptions may be required in the following cases:

a) User-defined constants using any of the names "plus", "minus",
"times", "less" or "less_eq". The standard syntax translations for
"+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
names.

b) Variables named "plus", "minus", "times", "less", "less_eq"
INCOMPATIBILITY: use more specific names.

c) Permutative equations (e.g. "a + b = b + a")
Since the change of names also changes the order of terms, permutative
rewrite rules may get applied in a different order. Experience shows
that this is rarely the case (only two adaptions in the whole Isabelle
distribution).  INCOMPATIBILITY: rewrite proofs

d) ML code directly refering to constant names
This in general only affects hand-written proof tactics, simprocs and
so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
Consider using @{const_name} antiquotation.

* New class "default" with associated constant "default".

* Function "sgn" is now overloaded and available on int, real, complex
(and other numeric types), using class "sgn".  Two possible defs of
sgn are given as equational assumptions in the classes sgn_if and
sgn_div_norm; ordered_idom now also inherits from sgn_if.
INCOMPATIBILITY.

* Locale "partial_order" now unified with class "order" (cf. theory
Orderings), added parameter "less".  INCOMPATIBILITY.

* Renamings in classes "order" and "linorder": facts "refl", "trans" and
"cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
clashes with HOL "refl" and "trans".  INCOMPATIBILITY.

* Classes "order" and "linorder": potential INCOMPATIBILITY due to
changed order of proof goals in instance proofs.

* The transitivity reasoner for partial and linear orders is set up
for classes "order" and "linorder".  Instances of the reasoner are available
in all contexts importing or interpreting the corresponding locales.
Method "order" invokes the reasoner separately; the reasoner
is also integrated with the Simplifier as a solver.  Diagnostic
command 'print_orders' shows the available instances of the reasoner
in the current context.

* Localized monotonicity predicate in theory "Orderings"; integrated
lemmas max_of_mono and min_of_mono with this predicate.
INCOMPATIBILITY.

* Formulation of theorem "dense" changed slightly due to integration
with new class dense_linear_order.

* Uniform lattice theory development in HOL.

    constants "meet" and "join" now named "inf" and "sup"
    constant "Meet" now named "Inf"

    classes "meet_semilorder" and "join_semilorder" now named
      "lower_semilattice" and "upper_semilattice"
    class "lorder" now named "lattice"
    class "comp_lat" now named "complete_lattice"

    Instantiation of lattice classes allows explicit definitions
    for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).

  INCOMPATIBILITY.  Theorem renames:

    meet_left_le            ~> inf_le1
    meet_right_le           ~> inf_le2
    join_left_le            ~> sup_ge1
    join_right_le           ~> sup_ge2
    meet_join_le            ~> inf_sup_ord
    le_meetI                ~> le_infI
    join_leI                ~> le_supI
    le_meet                 ~> le_inf_iff
    le_join                 ~> ge_sup_conv
    meet_idempotent         ~> inf_idem
    join_idempotent         ~> sup_idem
    meet_comm               ~> inf_commute
    join_comm               ~> sup_commute
    meet_leI1               ~> le_infI1
    meet_leI2               ~> le_infI2
    le_joinI1               ~> le_supI1
    le_joinI2               ~> le_supI2
    meet_assoc              ~> inf_assoc
    join_assoc              ~> sup_assoc
    meet_left_comm          ~> inf_left_commute
    meet_left_idempotent    ~> inf_left_idem
    join_left_comm          ~> sup_left_commute
    join_left_idempotent    ~> sup_left_idem
    meet_aci                ~> inf_aci
    join_aci                ~> sup_aci
    le_def_meet             ~> le_iff_inf
    le_def_join             ~> le_iff_sup
    join_absorp2            ~> sup_absorb2
    join_absorp1            ~> sup_absorb1
    meet_absorp1            ~> inf_absorb1
    meet_absorp2            ~> inf_absorb2
    meet_join_absorp        ~> inf_sup_absorb
    join_meet_absorp        ~> sup_inf_absorb
    distrib_join_le         ~> distrib_sup_le
    distrib_meet_le         ~> distrib_inf_le

    add_meet_distrib_left   ~> add_inf_distrib_left
    add_join_distrib_left   ~> add_sup_distrib_left
    is_join_neg_meet        ~> is_join_neg_inf
    is_meet_neg_join        ~> is_meet_neg_sup
    add_meet_distrib_right  ~> add_inf_distrib_right
    add_join_distrib_right  ~> add_sup_distrib_right
    add_meet_join_distribs  ~> add_sup_inf_distribs
    join_eq_neg_meet        ~> sup_eq_neg_inf
    meet_eq_neg_join        ~> inf_eq_neg_sup
    add_eq_meet_join        ~> add_eq_inf_sup
    meet_0_imp_0            ~> inf_0_imp_0
    join_0_imp_0            ~> sup_0_imp_0
    meet_0_eq_0             ~> inf_0_eq_0
    join_0_eq_0             ~> sup_0_eq_0
    neg_meet_eq_join        ~> neg_inf_eq_sup
    neg_join_eq_meet        ~> neg_sup_eq_inf
    join_eq_if              ~> sup_eq_if

    mono_meet               ~> mono_inf
    mono_join               ~> mono_sup
    meet_bool_eq            ~> inf_bool_eq
    join_bool_eq            ~> sup_bool_eq
    meet_fun_eq             ~> inf_fun_eq
    join_fun_eq             ~> sup_fun_eq
    meet_set_eq             ~> inf_set_eq
    join_set_eq             ~> sup_set_eq
    meet1_iff               ~> inf1_iff
    meet2_iff               ~> inf2_iff
    meet1I                  ~> inf1I
    meet2I                  ~> inf2I
    meet1D1                 ~> inf1D1
    meet2D1                 ~> inf2D1
    meet1D2                 ~> inf1D2
    meet2D2                 ~> inf2D2
    meet1E                  ~> inf1E
    meet2E                  ~> inf2E
    join1_iff               ~> sup1_iff
    join2_iff               ~> sup2_iff
    join1I1                 ~> sup1I1
    join2I1                 ~> sup2I1
    join1I1                 ~> sup1I1
    join2I2                 ~> sup1I2
    join1CI                 ~> sup1CI
    join2CI                 ~> sup2CI
    join1E                  ~> sup1E
    join2E                  ~> sup2E

    is_meet_Meet            ~> is_meet_Inf
    Meet_bool_def           ~> Inf_bool_def
    Meet_fun_def            ~> Inf_fun_def
    Meet_greatest           ~> Inf_greatest
    Meet_lower              ~> Inf_lower
    Meet_set_def            ~> Inf_set_def

    Sup_def                 ~> Sup_Inf
    Sup_bool_eq             ~> Sup_bool_def
    Sup_fun_eq              ~> Sup_fun_def
    Sup_set_eq              ~> Sup_set_def

    listsp_meetI            ~> listsp_infI
    listsp_meet_eq          ~> listsp_inf_eq

    meet_min                ~> inf_min
    join_max                ~> sup_max

* Added syntactic class "size"; overloaded constant "size" now has
type "'a::size ==> bool"

* Internal reorganisation of `size' of datatypes: size theorems
"foo.size" are no longer subsumed by "foo.simps" (but are still
simplification rules by default!); theorems "prod.size" now named
"*.size".

* Class "div" now inherits from class "times" rather than "type".
INCOMPATIBILITY.

* HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
Linorder etc.  have disappeared; operations defined in terms of
fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.

* HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.

* HOL-Word: New extensive library and type for generic, fixed size
machine words, with arithemtic, bit-wise, shifting and rotating
operations, reflection into int, nat, and bool lists, automation for
linear arithmetic (by automatic reflection into nat or int), including
lemmas on overflow and monotonicity.  Instantiated to all appropriate
arithmetic type classes, supporting automatic simplification of
numerals on all operations.

* Library/Boolean_Algebra: locales for abstract boolean algebras.

* Library/Numeral_Type: numbers as types, e.g. TYPE(32).

* Code generator library theories:
  - Code_Integer represents HOL integers by big integer literals in target
    languages.
  - Code_Char represents HOL characters by character literals in target
    languages.
  - Code_Char_chr like Code_Char, but also offers treatment of character
    codes; includes Code_Integer.
  - Executable_Set allows to generate code for finite sets using lists.
  - Executable_Rat implements rational numbers as triples (sign, enumerator,
    denominator).
  - Executable_Real implements a subset of real numbers, namly those
    representable by rational numbers.
  - Efficient_Nat implements natural numbers by integers, which in general will
    result in higher efficency; pattern matching with 0/Suc is eliminated;
    includes Code_Integer.
  - Code_Index provides an additional datatype index which is mapped to
    target-language built-in integers.
  - Code_Message provides an additional datatype message_string which is isomorphic to
    strings; messages are mapped to target-language strings.

* New package for inductive predicates

  An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via

    inductive
      p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
      for z_1 :: U_1 and ... and z_n :: U_m
    where
      rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
    | ...

  with full support for type-inference, rather than

    consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"

    abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
    where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"

    inductive "s z_1 ... z_m"
    intros
      rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
      ...

  For backward compatibility, there is a wrapper allowing inductive
  sets to be defined with the new package via

    inductive_set
      s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
      for z_1 :: U_1 and ... and z_n :: U_m
    where
      rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
    | ...

  or

    inductive_set
      s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
      and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
      for z_1 :: U_1 and ... and z_n :: U_m
    where
      "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
    | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
    | ...

  if the additional syntax "p ..." is required.

  Numerous examples can be found in the subdirectories src/HOL/Auth,
  src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.

  INCOMPATIBILITIES:

  - Since declaration and definition of inductive sets or predicates
    is no longer separated, abbreviations involving the newly
    introduced sets or predicates must be specified together with the
    introduction rules after the 'where' keyword (see above), rather
    than before the actual inductive definition.

  - The variables in induction and elimination rules are now
    quantified in the order of their occurrence in the introduction
    rules, rather than in alphabetical order. Since this may break
    some proofs, these proofs either have to be repaired, e.g. by
    reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
    statements of the form

      case (rule_i a_i_1 ... a_i_{k_i})

    or the old order of quantification has to be restored by explicitly adding
    meta-level quantifiers in the introduction rules, i.e.

      | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"

  - The format of the elimination rules is now

      p z_1 ... z_m x_1 ... x_n ==>
        (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
        ==> ... ==> P

    for predicates and

      (x_1, ..., x_n) : s z_1 ... z_m ==>
        (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
        ==> ... ==> P

    for sets rather than

      x : s z_1 ... z_m ==>
        (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
        ==> ... ==> P

    This may require terms in goals to be expanded to n-tuples
    (e.g. using case_tac or simplification with the split_paired_all
    rule) before the above elimination rule is applicable.

  - The elimination or case analysis rules for (mutually) inductive
    sets or predicates are now called "p_1.cases" ... "p_k.cases". The
    list of rules "p_1_..._p_k.elims" is no longer available.

* New package "function"/"fun" for general recursive functions,
supporting mutual and nested recursion, definitions in local contexts,
more general pattern matching and partiality. See HOL/ex/Fundefs.thy
for small examples, and the separate tutorial on the function
package. The old recdef "package" is still available as before, but
users are encouraged to use the new package.

* Method "lexicographic_order" automatically synthesizes termination
relations as lexicographic combinations of size measures. 

* Case-expressions allow arbitrary constructor-patterns (including
"_") and take their order into account, like in functional
programming.  Internally, this is translated into nested
case-expressions; missing cases are added and mapped to the predefined
constant "undefined". In complicated cases printing may no longer show
the original input but the internal form. Lambda-abstractions allow
the same form of pattern matching: "% pat1 => e1 | ..." is an
abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
variable.

* IntDef: The constant "int :: nat => int" has been removed; now "int"
is an abbreviation for "of_nat :: nat => int". The simplification
rules for "of_nat" have been changed to work like "int" did
previously.  Potential INCOMPATIBILITY:
  - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  - of_nat_diff and of_nat_mult are no longer default simp rules

* Method "algebra" solves polynomial equations over (semi)rings using
Groebner bases. The (semi)ring structure is defined by locales and the
tool setup depends on that generic context. Installing the method for
a specific type involves instantiating the locale and possibly adding
declarations for computation on the coefficients.  The method is
already instantiated for natural numbers and for the axiomatic class
of idoms with numerals.  See also the paper by Chaieb and Wenzel at
CALCULEMUS 2007 for the general principles underlying this
architecture of context-aware proof-tools.

* Method "ferrack" implements quantifier elimination over
special-purpose dense linear orders using locales (analogous to
"algebra"). The method is already installed for class
{ordered_field,recpower,number_ring} which subsumes real, hyperreal,
rat, etc.

* Former constant "List.op @" now named "List.append".  Use ML
antiquotations @{const_name List.append} or @{term " ... @ ... "} to
circumvent possible incompatibilities when working on ML level.

* primrec: missing cases mapped to "undefined" instead of "arbitrary".

* New function listsum :: 'a list => 'a for arbitrary monoids.
Special syntax: "SUM x <- xs. f x" (and latex variants)

* New syntax for Haskell-like list comprehension (input only), eg.
[(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.