src/HOL/Set.thy
author wenzelm
Fri Nov 02 22:01:58 2001 +0100 (2001-11-02)
changeset 12020 a24373086908
parent 11982 65e2822d83dd
child 12023 d982f98e0f0d
permissions -rw-r--r--
theory Calculation move to Set;
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(*  Title:      HOL/Set.thy
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    ID:         $Id$
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    Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen
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    License:    GPL (GNU GENERAL PUBLIC LICENSE)
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*)
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header {* Set theory for higher-order logic *}
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theory Set = HOL
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files ("subset.ML") ("equalities.ML") ("mono.ML"):
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text {* A set in HOL is simply a predicate. *}
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subsection {* Basic syntax *}
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global
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typedecl 'a set
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arities set :: ("term") "term"
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consts
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  "{}"          :: "'a set"                             ("{}")
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  UNIV          :: "'a set"
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  insert        :: "'a => 'a set => 'a set"
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  Collect       :: "('a => bool) => 'a set"              -- "comprehension"
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  Int           :: "'a set => 'a set => 'a set"          (infixl 70)
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  Un            :: "'a set => 'a set => 'a set"          (infixl 65)
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  UNION         :: "'a set => ('a => 'b set) => 'b set"  -- "general union"
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  INTER         :: "'a set => ('a => 'b set) => 'b set"  -- "general intersection"
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  Union         :: "'a set set => 'a set"                -- "union of a set"
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  Inter         :: "'a set set => 'a set"                -- "intersection of a set"
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  Pow           :: "'a set => 'a set set"                -- "powerset"
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  Ball          :: "'a set => ('a => bool) => bool"      -- "bounded universal quantifiers"
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  Bex           :: "'a set => ('a => bool) => bool"      -- "bounded existential quantifiers"
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  image         :: "('a => 'b) => 'a set => 'b set"      (infixr "`" 90)
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syntax
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  "op :"        :: "'a => 'a set => bool"                ("op :")
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consts
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  "op :"        :: "'a => 'a set => bool"                ("(_/ : _)" [50, 51] 50)  -- "membership"
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local
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instance set :: ("term") ord ..
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instance set :: ("term") minus ..
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subsection {* Additional concrete syntax *}
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syntax
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  range         :: "('a => 'b) => 'b set"             -- "of function"
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  "op ~:"       :: "'a => 'a set => bool"                 ("op ~:")  -- "non-membership"
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  "op ~:"       :: "'a => 'a set => bool"                 ("(_/ ~: _)" [50, 51] 50)
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  "@Finset"     :: "args => 'a set"                       ("{(_)}")
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  "@Coll"       :: "pttrn => bool => 'a set"              ("(1{_./ _})")
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  "@SetCompr"   :: "'a => idts => bool => 'a set"         ("(1{_ |/_./ _})")
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  "@INTER1"     :: "pttrns => 'b set => 'b set"           ("(3INT _./ _)" 10)
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  "@UNION1"     :: "pttrns => 'b set => 'b set"           ("(3UN _./ _)" 10)
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  "@INTER"      :: "pttrn => 'a set => 'b set => 'b set"  ("(3INT _:_./ _)" 10)
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  "@UNION"      :: "pttrn => 'a set => 'b set => 'b set"  ("(3UN _:_./ _)" 10)
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  "_Ball"       :: "pttrn => 'a set => bool => bool"      ("(3ALL _:_./ _)" [0, 0, 10] 10)
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  "_Bex"        :: "pttrn => 'a set => bool => bool"      ("(3EX _:_./ _)" [0, 0, 10] 10)
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syntax (HOL)
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  "_Ball"       :: "pttrn => 'a set => bool => bool"      ("(3! _:_./ _)" [0, 0, 10] 10)
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  "_Bex"        :: "pttrn => 'a set => bool => bool"      ("(3? _:_./ _)" [0, 0, 10] 10)
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translations
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  "range f"     == "f`UNIV"
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  "x ~: y"      == "~ (x : y)"
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  "{x, xs}"     == "insert x {xs}"
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  "{x}"         == "insert x {}"
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  "{x. P}"      == "Collect (%x. P)"
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  "UN x y. B"   == "UN x. UN y. B"
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  "UN x. B"     == "UNION UNIV (%x. B)"
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  "INT x y. B"  == "INT x. INT y. B"
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  "INT x. B"    == "INTER UNIV (%x. B)"
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  "UN x:A. B"   == "UNION A (%x. B)"
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  "INT x:A. B"  == "INTER A (%x. B)"
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  "ALL x:A. P"  == "Ball A (%x. P)"
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  "EX x:A. P"   == "Bex A (%x. P)"
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syntax ("" output)
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  "_setle"      :: "'a set => 'a set => bool"             ("op <=")
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  "_setle"      :: "'a set => 'a set => bool"             ("(_/ <= _)" [50, 51] 50)
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  "_setless"    :: "'a set => 'a set => bool"             ("op <")
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  "_setless"    :: "'a set => 'a set => bool"             ("(_/ < _)" [50, 51] 50)
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syntax (symbols)
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  "_setle"      :: "'a set => 'a set => bool"             ("op \<subseteq>")
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  "_setle"      :: "'a set => 'a set => bool"             ("(_/ \<subseteq> _)" [50, 51] 50)
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  "_setless"    :: "'a set => 'a set => bool"             ("op \<subset>")
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  "_setless"    :: "'a set => 'a set => bool"             ("(_/ \<subset> _)" [50, 51] 50)
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  "op Int"      :: "'a set => 'a set => 'a set"           (infixl "\<inter>" 70)
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  "op Un"       :: "'a set => 'a set => 'a set"           (infixl "\<union>" 65)
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  "op :"        :: "'a => 'a set => bool"                 ("op \<in>")
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  "op :"        :: "'a => 'a set => bool"                 ("(_/ \<in> _)" [50, 51] 50)
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  "op ~:"       :: "'a => 'a set => bool"                 ("op \<notin>")
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  "op ~:"       :: "'a => 'a set => bool"                 ("(_/ \<notin> _)" [50, 51] 50)
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  "@UNION1"     :: "pttrns => 'b set => 'b set"           ("(3\<Union>_./ _)" 10)
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  "@INTER1"     :: "pttrns => 'b set => 'b set"           ("(3\<Inter>_./ _)" 10)
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  "@UNION"      :: "pttrn => 'a set => 'b set => 'b set"  ("(3\<Union>_\<in>_./ _)" 10)
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  "@INTER"      :: "pttrn => 'a set => 'b set => 'b set"  ("(3\<Inter>_\<in>_./ _)" 10)
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  Union         :: "'a set set => 'a set"                 ("\<Union>_" [90] 90)
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  Inter         :: "'a set set => 'a set"                 ("\<Inter>_" [90] 90)
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  "_Ball"       :: "pttrn => 'a set => bool => bool"      ("(3\<forall>_\<in>_./ _)" [0, 0, 10] 10)
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  "_Bex"        :: "pttrn => 'a set => bool => bool"      ("(3\<exists>_\<in>_./ _)" [0, 0, 10] 10)
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translations
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  "op \<subseteq>" => "op <= :: _ set => _ set => bool"
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  "op \<subset>" => "op <  :: _ set => _ set => bool"
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typed_print_translation {*
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  let
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    fun le_tr' _ (Type ("fun", (Type ("set", _) :: _))) ts =
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          list_comb (Syntax.const "_setle", ts)
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      | le_tr' _ _ _ = raise Match;
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    fun less_tr' _ (Type ("fun", (Type ("set", _) :: _))) ts =
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          list_comb (Syntax.const "_setless", ts)
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      | less_tr' _ _ _ = raise Match;
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  in [("op <=", le_tr'), ("op <", less_tr')] end
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*}
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text {*
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  \medskip Translate between @{text "{e | x1...xn. P}"} and @{text
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  "{u. EX x1..xn. u = e & P}"}; @{text "{y. EX x1..xn. y = e & P}"} is
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  only translated if @{text "[0..n] subset bvs(e)"}.
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*}
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parse_translation {*
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  let
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    val ex_tr = snd (mk_binder_tr ("EX ", "Ex"));
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    fun nvars (Const ("_idts", _) $ _ $ idts) = nvars idts + 1
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      | nvars _ = 1;
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    fun setcompr_tr [e, idts, b] =
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      let
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        val eq = Syntax.const "op =" $ Bound (nvars idts) $ e;
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        val P = Syntax.const "op &" $ eq $ b;
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        val exP = ex_tr [idts, P];
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      in Syntax.const "Collect" $ Abs ("", dummyT, exP) end;
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  in [("@SetCompr", setcompr_tr)] end;
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*}
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print_translation {*
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  let
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    val ex_tr' = snd (mk_binder_tr' ("Ex", "DUMMY"));
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    fun setcompr_tr' [Abs (_, _, P)] =
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      let
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        fun check (Const ("Ex", _) $ Abs (_, _, P), n) = check (P, n + 1)
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          | check (Const ("op &", _) $ (Const ("op =", _) $ Bound m $ e) $ P, n) =
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              if n > 0 andalso m = n andalso not (loose_bvar1 (P, n)) andalso
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                ((0 upto (n - 1)) subset add_loose_bnos (e, 0, [])) then ()
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              else raise Match;
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        fun tr' (_ $ abs) =
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          let val _ $ idts $ (_ $ (_ $ _ $ e) $ Q) = ex_tr' [abs]
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          in Syntax.const "@SetCompr" $ e $ idts $ Q end;
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      in check (P, 0); tr' P end;
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  in [("Collect", setcompr_tr')] end;
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*}
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subsection {* Rules and definitions *}
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text {* Isomorphisms between predicates and sets. *}
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axioms
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  mem_Collect_eq [iff]: "(a : {x. P(x)}) = P(a)"
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  Collect_mem_eq [simp]: "{x. x:A} = A"
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defs
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  Ball_def:     "Ball A P       == ALL x. x:A --> P(x)"
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  Bex_def:      "Bex A P        == EX x. x:A & P(x)"
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defs (overloaded)
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  subset_def:   "A <= B         == ALL x:A. x:B"
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  psubset_def:  "A < B          == (A::'a set) <= B & ~ A=B"
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  Compl_def:    "- A            == {x. ~x:A}"
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defs
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  Un_def:       "A Un B         == {x. x:A | x:B}"
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  Int_def:      "A Int B        == {x. x:A & x:B}"
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  set_diff_def: "A - B          == {x. x:A & ~x:B}"
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  INTER_def:    "INTER A B      == {y. ALL x:A. y: B(x)}"
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  UNION_def:    "UNION A B      == {y. EX x:A. y: B(x)}"
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  Inter_def:    "Inter S        == (INT x:S. x)"
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  Union_def:    "Union S        == (UN x:S. x)"
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  Pow_def:      "Pow A          == {B. B <= A}"
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  empty_def:    "{}             == {x. False}"
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  UNIV_def:     "UNIV           == {x. True}"
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  insert_def:   "insert a B     == {x. x=a} Un B"
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  image_def:    "f`A            == {y. EX x:A. y = f(x)}"
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subsection {* Lemmas and proof tool setup *}
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subsubsection {* Relating predicates and sets *}
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lemma CollectI [intro!]: "P(a) ==> a : {x. P(x)}"
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  by simp
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lemma CollectD: "a : {x. P(x)} ==> P(a)"
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  by simp
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lemma set_ext: "(!!x. (x:A) = (x:B)) ==> A = B"
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proof -
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  case rule_context
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  show ?thesis
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    apply (rule prems [THEN ext, THEN arg_cong, THEN box_equals])
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     apply (rule Collect_mem_eq)
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    apply (rule Collect_mem_eq)
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    done
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qed
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lemma Collect_cong: "(!!x. P x = Q x) ==> {x. P(x)} = {x. Q(x)}"
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  by simp
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lemmas CollectE [elim!] = CollectD [elim_format]
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subsubsection {* Bounded quantifiers *}
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lemma ballI [intro!]: "(!!x. x:A ==> P x) ==> ALL x:A. P x"
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  by (simp add: Ball_def)
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lemmas strip = impI allI ballI
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lemma bspec [dest?]: "ALL x:A. P x ==> x:A ==> P x"
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  by (simp add: Ball_def)
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lemma ballE [elim]: "ALL x:A. P x ==> (P x ==> Q) ==> (x ~: A ==> Q) ==> Q"
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  by (unfold Ball_def) blast
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text {*
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  \medskip This tactic takes assumptions @{prop "ALL x:A. P x"} and
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  @{prop "a:A"}; creates assumption @{prop "P a"}.
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*}
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ML {*
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  local val ballE = thm "ballE"
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  in fun ball_tac i = etac ballE i THEN contr_tac (i + 1) end;
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*}
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text {*
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  Gives better instantiation for bound:
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*}
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ML_setup {*
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  claset_ref() := claset() addbefore ("bspec", datac (thm "bspec") 1);
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*}
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lemma bexI [intro]: "P x ==> x:A ==> EX x:A. P x"
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  -- {* Normally the best argument order: @{prop "P x"} constrains the
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    choice of @{prop "x:A"}. *}
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  by (unfold Bex_def) blast
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lemma rev_bexI: "x:A ==> P x ==> EX x:A. P x"
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  -- {* The best argument order when there is only one @{prop "x:A"}. *}
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  by (unfold Bex_def) blast
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lemma bexCI: "(ALL x:A. ~P x ==> P a) ==> a:A ==> EX x:A. P x"
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  by (unfold Bex_def) blast
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lemma bexE [elim!]: "EX x:A. P x ==> (!!x. x:A ==> P x ==> Q) ==> Q"
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  by (unfold Bex_def) blast
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lemma ball_triv [simp]: "(ALL x:A. P) = ((EX x. x:A) --> P)"
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  -- {* Trival rewrite rule. *}
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  by (simp add: Ball_def)
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lemma bex_triv [simp]: "(EX x:A. P) = ((EX x. x:A) & P)"
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  -- {* Dual form for existentials. *}
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  by (simp add: Bex_def)
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lemma bex_triv_one_point1 [simp]: "(EX x:A. x = a) = (a:A)"
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  by blast
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lemma bex_triv_one_point2 [simp]: "(EX x:A. a = x) = (a:A)"
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  by blast
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lemma bex_one_point1 [simp]: "(EX x:A. x = a & P x) = (a:A & P a)"
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  by blast
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lemma bex_one_point2 [simp]: "(EX x:A. a = x & P x) = (a:A & P a)"
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  by blast
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lemma ball_one_point1 [simp]: "(ALL x:A. x = a --> P x) = (a:A --> P a)"
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   299
  by blast
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   300
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   301
lemma ball_one_point2 [simp]: "(ALL x:A. a = x --> P x) = (a:A --> P a)"
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   302
  by blast
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   303
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   304
ML_setup {*
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   305
  let
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   306
    val Ball_def = thm "Ball_def";
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   307
    val Bex_def = thm "Bex_def";
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   308
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   309
    val ex_pattern = Thm.read_cterm (Theory.sign_of (the_context ()))
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   310
      ("EX x:A. P x & Q x", HOLogic.boolT);
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   311
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   312
    val prove_bex_tac =
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   313
      rewrite_goals_tac [Bex_def] THEN Quantifier1.prove_one_point_ex_tac;
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   314
    val rearrange_bex = Quantifier1.rearrange_bex prove_bex_tac;
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   315
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   316
    val all_pattern = Thm.read_cterm (Theory.sign_of (the_context ()))
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   317
      ("ALL x:A. P x --> Q x", HOLogic.boolT);
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   318
wenzelm@11979
   319
    val prove_ball_tac =
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   320
      rewrite_goals_tac [Ball_def] THEN Quantifier1.prove_one_point_all_tac;
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   321
    val rearrange_ball = Quantifier1.rearrange_ball prove_ball_tac;
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   322
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   323
    val defBEX_regroup = mk_simproc "defined BEX" [ex_pattern] rearrange_bex;
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   324
    val defBALL_regroup = mk_simproc "defined BALL" [all_pattern] rearrange_ball;
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   325
  in
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   326
    Addsimprocs [defBALL_regroup, defBEX_regroup]
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   327
  end;
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   328
*}
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   329
wenzelm@11979
   330
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   331
subsubsection {* Congruence rules *}
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   332
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   333
lemma ball_cong [cong]:
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   334
  "A = B ==> (!!x. x:B ==> P x = Q x) ==>
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   335
    (ALL x:A. P x) = (ALL x:B. Q x)"
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   336
  by (simp add: Ball_def)
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   337
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   338
lemma bex_cong [cong]:
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   339
  "A = B ==> (!!x. x:B ==> P x = Q x) ==>
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   340
    (EX x:A. P x) = (EX x:B. Q x)"
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   341
  by (simp add: Bex_def cong: conj_cong)
regensbu@1273
   342
wenzelm@7238
   343
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   344
subsubsection {* Subsets *}
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   345
wenzelm@11979
   346
lemma subsetI [intro!]: "(!!x. x:A ==> x:B) ==> A <= B"
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   347
  by (simp add: subset_def)
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   348
wenzelm@11979
   349
text {*
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   350
  \medskip Map the type @{text "'a set => anything"} to just @{typ
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   351
  'a}; for overloading constants whose first argument has type @{typ
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   352
  "'a set"}.
wenzelm@11979
   353
*}
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   354
wenzelm@11979
   355
ML {*
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   356
  fun overload_1st_set s = Blast.overloaded (s, HOLogic.dest_setT o domain_type);
wenzelm@11979
   357
*}
wenzelm@11979
   358
wenzelm@11979
   359
ML "
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   360
  (* While (:) is not, its type must be kept
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   361
    for overloading of = to work. *)
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   362
  Blast.overloaded (\"op :\", domain_type);
wenzelm@11979
   363
wenzelm@11979
   364
  overload_1st_set \"Ball\";            (*need UNION, INTER also?*)
wenzelm@11979
   365
  overload_1st_set \"Bex\";
wenzelm@11979
   366
wenzelm@11979
   367
  (*Image: retain the type of the set being expressed*)
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   368
  Blast.overloaded (\"image\", domain_type);
wenzelm@11979
   369
"
wenzelm@11979
   370
wenzelm@11979
   371
lemma subsetD [elim]: "A <= B ==> c:A ==> c:B"
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   372
  -- {* Rule in Modus Ponens style. *}
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   373
  by (unfold subset_def) blast
wenzelm@11979
   374
wenzelm@11979
   375
declare subsetD [intro?] -- FIXME
wenzelm@11979
   376
wenzelm@11979
   377
lemma rev_subsetD: "c:A ==> A <= B ==> c:B"
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   378
  -- {* The same, with reversed premises for use with @{text erule} --
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   379
      cf @{text rev_mp}. *}
wenzelm@11979
   380
  by (rule subsetD)
wenzelm@11979
   381
wenzelm@11979
   382
declare rev_subsetD [intro?] -- FIXME
wenzelm@11979
   383
wenzelm@11979
   384
text {*
wenzelm@11979
   385
  \medskip Converts @{prop "A <= B"} to @{prop "x:A ==> x:B"}.
wenzelm@11979
   386
*}
wenzelm@11979
   387
wenzelm@11979
   388
ML {*
wenzelm@11979
   389
  local val rev_subsetD = thm "rev_subsetD"
wenzelm@11979
   390
  in fun impOfSubs th = th RSN (2, rev_subsetD) end;
wenzelm@11979
   391
*}
wenzelm@11979
   392
wenzelm@11979
   393
lemma subsetCE [elim]: "A <= B ==> (c~:A ==> P) ==> (c:B ==> P) ==> P"
wenzelm@11979
   394
  -- {* Classical elimination rule. *}
wenzelm@11979
   395
  by (unfold subset_def) blast
wenzelm@11979
   396
wenzelm@11979
   397
text {*
wenzelm@11979
   398
  \medskip Takes assumptions @{prop "A <= B"}; @{prop "c:A"} and
wenzelm@11979
   399
  creates the assumption @{prop "c:B"}.
wenzelm@11979
   400
*}
wenzelm@11979
   401
wenzelm@11979
   402
ML {*
wenzelm@11979
   403
  local val subsetCE = thm "subsetCE"
wenzelm@11979
   404
  in fun set_mp_tac i = etac subsetCE i THEN mp_tac i end;
wenzelm@11979
   405
*}
wenzelm@11979
   406
wenzelm@11979
   407
lemma contra_subsetD: "A <= B ==> c ~: B ==> c ~: A"
wenzelm@11979
   408
  by blast
wenzelm@11979
   409
wenzelm@11979
   410
lemma subset_refl: "A <= (A::'a set)"
wenzelm@11979
   411
  by fast
wenzelm@11979
   412
wenzelm@11979
   413
lemma subset_trans: "A <= B ==> B <= C ==> A <= (C::'a set)"
wenzelm@11979
   414
  by blast
clasohm@923
   415
wenzelm@2261
   416
wenzelm@11979
   417
subsubsection {* Equality *}
wenzelm@11979
   418
wenzelm@11979
   419
lemma subset_antisym [intro!]: "A <= B ==> B <= A ==> A = (B::'a set)"
wenzelm@11979
   420
  -- {* Anti-symmetry of the subset relation. *}
wenzelm@11979
   421
  by (rule set_ext) (blast intro: subsetD)
wenzelm@11979
   422
wenzelm@11979
   423
lemmas equalityI = subset_antisym
wenzelm@11979
   424
wenzelm@11979
   425
text {*
wenzelm@11979
   426
  \medskip Equality rules from ZF set theory -- are they appropriate
wenzelm@11979
   427
  here?
wenzelm@11979
   428
*}
wenzelm@11979
   429
wenzelm@11979
   430
lemma equalityD1: "A = B ==> A <= (B::'a set)"
wenzelm@11979
   431
  by (simp add: subset_refl)
wenzelm@11979
   432
wenzelm@11979
   433
lemma equalityD2: "A = B ==> B <= (A::'a set)"
wenzelm@11979
   434
  by (simp add: subset_refl)
wenzelm@11979
   435
wenzelm@11979
   436
text {*
wenzelm@11979
   437
  \medskip Be careful when adding this to the claset as @{text
wenzelm@11979
   438
  subset_empty} is in the simpset: @{prop "A = {}"} goes to @{prop "{}
wenzelm@11979
   439
  <= A"} and @{prop "A <= {}"} and then back to @{prop "A = {}"}!
wenzelm@11979
   440
*}
wenzelm@11979
   441
wenzelm@11979
   442
lemma equalityE: "A = B ==> (A <= B ==> B <= (A::'a set) ==> P) ==> P"
wenzelm@11979
   443
  by (simp add: subset_refl)
clasohm@923
   444
wenzelm@11979
   445
lemma equalityCE [elim]:
wenzelm@11979
   446
    "A = B ==> (c:A ==> c:B ==> P) ==> (c~:A ==> c~:B ==> P) ==> P"
wenzelm@11979
   447
  by blast
wenzelm@11979
   448
wenzelm@11979
   449
text {*
wenzelm@11979
   450
  \medskip Lemma for creating induction formulae -- for "pattern
wenzelm@11979
   451
  matching" on @{text p}.  To make the induction hypotheses usable,
wenzelm@11979
   452
  apply @{text spec} or @{text bspec} to put universal quantifiers over the free
wenzelm@11979
   453
  variables in @{text p}.
wenzelm@11979
   454
*}
wenzelm@11979
   455
wenzelm@11979
   456
lemma setup_induction: "p:A ==> (!!z. z:A ==> p = z --> R) ==> R"
wenzelm@11979
   457
  by simp
clasohm@923
   458
wenzelm@11979
   459
lemma eqset_imp_iff: "A = B ==> (x : A) = (x : B)"
wenzelm@11979
   460
  by simp
wenzelm@11979
   461
wenzelm@11979
   462
wenzelm@11979
   463
subsubsection {* The universal set -- UNIV *}
wenzelm@11979
   464
wenzelm@11979
   465
lemma UNIV_I [simp]: "x : UNIV"
wenzelm@11979
   466
  by (simp add: UNIV_def)
wenzelm@11979
   467
wenzelm@11979
   468
declare UNIV_I [intro]  -- {* unsafe makes it less likely to cause problems *}
wenzelm@11979
   469
wenzelm@11979
   470
lemma UNIV_witness [intro?]: "EX x. x : UNIV"
wenzelm@11979
   471
  by simp
wenzelm@11979
   472
wenzelm@11979
   473
lemma subset_UNIV: "A <= UNIV"
wenzelm@11979
   474
  by (rule subsetI) (rule UNIV_I)
wenzelm@2388
   475
wenzelm@11979
   476
text {*
wenzelm@11979
   477
  \medskip Eta-contracting these two rules (to remove @{text P})
wenzelm@11979
   478
  causes them to be ignored because of their interaction with
wenzelm@11979
   479
  congruence rules.
wenzelm@11979
   480
*}
wenzelm@11979
   481
wenzelm@11979
   482
lemma ball_UNIV [simp]: "Ball UNIV P = All P"
wenzelm@11979
   483
  by (simp add: Ball_def)
wenzelm@11979
   484
wenzelm@11979
   485
lemma bex_UNIV [simp]: "Bex UNIV P = Ex P"
wenzelm@11979
   486
  by (simp add: Bex_def)
wenzelm@11979
   487
wenzelm@11979
   488
wenzelm@11979
   489
subsubsection {* The empty set *}
wenzelm@11979
   490
wenzelm@11979
   491
lemma empty_iff [simp]: "(c : {}) = False"
wenzelm@11979
   492
  by (simp add: empty_def)
wenzelm@11979
   493
wenzelm@11979
   494
lemma emptyE [elim!]: "a : {} ==> P"
wenzelm@11979
   495
  by simp
wenzelm@11979
   496
wenzelm@11979
   497
lemma empty_subsetI [iff]: "{} <= A"
wenzelm@11979
   498
    -- {* One effect is to delete the ASSUMPTION @{prop "{} <= A"} *}
wenzelm@11979
   499
  by blast
wenzelm@11979
   500
wenzelm@11979
   501
lemma equals0I: "(!!y. y:A ==> False) ==> A = {}"
wenzelm@11979
   502
  by blast
wenzelm@2388
   503
wenzelm@11979
   504
lemma equals0D: "A={} ==> a ~: A"
wenzelm@11979
   505
    -- {* Use for reasoning about disjointness: @{prop "A Int B = {}"} *}
wenzelm@11979
   506
  by blast
wenzelm@11979
   507
wenzelm@11979
   508
lemma ball_empty [simp]: "Ball {} P = True"
wenzelm@11979
   509
  by (simp add: Ball_def)
wenzelm@11979
   510
wenzelm@11979
   511
lemma bex_empty [simp]: "Bex {} P = False"
wenzelm@11979
   512
  by (simp add: Bex_def)
wenzelm@11979
   513
wenzelm@11979
   514
lemma UNIV_not_empty [iff]: "UNIV ~= {}"
wenzelm@11979
   515
  by (blast elim: equalityE)
wenzelm@11979
   516
wenzelm@11979
   517
wenzelm@11979
   518
section {* The Powerset operator -- Pow *}
wenzelm@11979
   519
wenzelm@11979
   520
lemma Pow_iff [iff]: "(A : Pow B) = (A <= B)"
wenzelm@11979
   521
  by (simp add: Pow_def)
wenzelm@11979
   522
wenzelm@11979
   523
lemma PowI: "A <= B ==> A : Pow B"
wenzelm@11979
   524
  by (simp add: Pow_def)
wenzelm@11979
   525
wenzelm@11979
   526
lemma PowD: "A : Pow B ==> A <= B"
wenzelm@11979
   527
  by (simp add: Pow_def)
wenzelm@11979
   528
wenzelm@11979
   529
lemma Pow_bottom: "{}: Pow B"
wenzelm@11979
   530
  by simp
wenzelm@11979
   531
wenzelm@11979
   532
lemma Pow_top: "A : Pow A"
wenzelm@11979
   533
  by (simp add: subset_refl)
wenzelm@2684
   534
wenzelm@2388
   535
wenzelm@11979
   536
subsubsection {* Set complement *}
wenzelm@11979
   537
wenzelm@11979
   538
lemma Compl_iff [simp]: "(c : -A) = (c~:A)"
wenzelm@11979
   539
  by (unfold Compl_def) blast
wenzelm@11979
   540
wenzelm@11979
   541
lemma ComplI [intro!]: "(c:A ==> False) ==> c : -A"
wenzelm@11979
   542
  by (unfold Compl_def) blast
wenzelm@11979
   543
wenzelm@11979
   544
text {*
wenzelm@11979
   545
  \medskip This form, with negated conclusion, works well with the
wenzelm@11979
   546
  Classical prover.  Negated assumptions behave like formulae on the
wenzelm@11979
   547
  right side of the notional turnstile ... *}
wenzelm@11979
   548
wenzelm@11979
   549
lemma ComplD: "c : -A ==> c~:A"
wenzelm@11979
   550
  by (unfold Compl_def) blast
wenzelm@11979
   551
wenzelm@11979
   552
lemmas ComplE [elim!] = ComplD [elim_format]
wenzelm@11979
   553
wenzelm@11979
   554
wenzelm@11979
   555
subsubsection {* Binary union -- Un *}
clasohm@923
   556
wenzelm@11979
   557
lemma Un_iff [simp]: "(c : A Un B) = (c:A | c:B)"
wenzelm@11979
   558
  by (unfold Un_def) blast
wenzelm@11979
   559
wenzelm@11979
   560
lemma UnI1 [elim?]: "c:A ==> c : A Un B"
wenzelm@11979
   561
  by simp
wenzelm@11979
   562
wenzelm@11979
   563
lemma UnI2 [elim?]: "c:B ==> c : A Un B"
wenzelm@11979
   564
  by simp
clasohm@923
   565
wenzelm@11979
   566
text {*
wenzelm@11979
   567
  \medskip Classical introduction rule: no commitment to @{prop A} vs
wenzelm@11979
   568
  @{prop B}.
wenzelm@11979
   569
*}
wenzelm@11979
   570
wenzelm@11979
   571
lemma UnCI [intro!]: "(c~:B ==> c:A) ==> c : A Un B"
wenzelm@11979
   572
  by auto
wenzelm@11979
   573
wenzelm@11979
   574
lemma UnE [elim!]: "c : A Un B ==> (c:A ==> P) ==> (c:B ==> P) ==> P"
wenzelm@11979
   575
  by (unfold Un_def) blast
wenzelm@11979
   576
wenzelm@11979
   577
wenzelm@12020
   578
subsection {* Binary intersection -- Int *}
clasohm@923
   579
wenzelm@11979
   580
lemma Int_iff [simp]: "(c : A Int B) = (c:A & c:B)"
wenzelm@11979
   581
  by (unfold Int_def) blast
wenzelm@11979
   582
wenzelm@11979
   583
lemma IntI [intro!]: "c:A ==> c:B ==> c : A Int B"
wenzelm@11979
   584
  by simp
wenzelm@11979
   585
wenzelm@11979
   586
lemma IntD1: "c : A Int B ==> c:A"
wenzelm@11979
   587
  by simp
wenzelm@11979
   588
wenzelm@11979
   589
lemma IntD2: "c : A Int B ==> c:B"
wenzelm@11979
   590
  by simp
wenzelm@11979
   591
wenzelm@11979
   592
lemma IntE [elim!]: "c : A Int B ==> (c:A ==> c:B ==> P) ==> P"
wenzelm@11979
   593
  by simp
wenzelm@11979
   594
wenzelm@11979
   595
wenzelm@12020
   596
subsection {* Set difference *}
wenzelm@11979
   597
wenzelm@11979
   598
lemma Diff_iff [simp]: "(c : A - B) = (c:A & c~:B)"
wenzelm@11979
   599
  by (unfold set_diff_def) blast
clasohm@923
   600
wenzelm@11979
   601
lemma DiffI [intro!]: "c : A ==> c ~: B ==> c : A - B"
wenzelm@11979
   602
  by simp
wenzelm@11979
   603
wenzelm@11979
   604
lemma DiffD1: "c : A - B ==> c : A"
wenzelm@11979
   605
  by simp
wenzelm@11979
   606
wenzelm@11979
   607
lemma DiffD2: "c : A - B ==> c : B ==> P"
wenzelm@11979
   608
  by simp
wenzelm@11979
   609
wenzelm@11979
   610
lemma DiffE [elim!]: "c : A - B ==> (c:A ==> c~:B ==> P) ==> P"
wenzelm@11979
   611
  by simp
wenzelm@11979
   612
wenzelm@11979
   613
wenzelm@11979
   614
subsubsection {* Augmenting a set -- insert *}
wenzelm@11979
   615
wenzelm@11979
   616
lemma insert_iff [simp]: "(a : insert b A) = (a = b | a:A)"
wenzelm@11979
   617
  by (unfold insert_def) blast
wenzelm@11979
   618
wenzelm@11979
   619
lemma insertI1: "a : insert a B"
wenzelm@11979
   620
  by simp
wenzelm@11979
   621
wenzelm@11979
   622
lemma insertI2: "a : B ==> a : insert b B"
wenzelm@11979
   623
  by simp
clasohm@923
   624
wenzelm@11979
   625
lemma insertE [elim!]: "a : insert b A ==> (a = b ==> P) ==> (a:A ==> P) ==> P"
wenzelm@11979
   626
  by (unfold insert_def) blast
wenzelm@11979
   627
wenzelm@11979
   628
lemma insertCI [intro!]: "(a~:B ==> a = b) ==> a: insert b B"
wenzelm@11979
   629
  -- {* Classical introduction rule. *}
wenzelm@11979
   630
  by auto
wenzelm@11979
   631
wenzelm@11979
   632
lemma subset_insert_iff: "(A <= insert x B) = (if x:A then A - {x} <= B else A <= B)"
wenzelm@11979
   633
  by auto
wenzelm@11979
   634
wenzelm@11979
   635
wenzelm@11979
   636
subsubsection {* Singletons, using insert *}
wenzelm@11979
   637
wenzelm@11979
   638
lemma singletonI [intro!]: "a : {a}"
wenzelm@11979
   639
    -- {* Redundant? But unlike @{text insertCI}, it proves the subgoal immediately! *}
wenzelm@11979
   640
  by (rule insertI1)
wenzelm@11979
   641
wenzelm@11979
   642
lemma singletonD: "b : {a} ==> b = a"
wenzelm@11979
   643
  by blast
wenzelm@11979
   644
wenzelm@11979
   645
lemmas singletonE [elim!] = singletonD [elim_format]
wenzelm@11979
   646
wenzelm@11979
   647
lemma singleton_iff: "(b : {a}) = (b = a)"
wenzelm@11979
   648
  by blast
wenzelm@11979
   649
wenzelm@11979
   650
lemma singleton_inject [dest!]: "{a} = {b} ==> a = b"
wenzelm@11979
   651
  by blast
wenzelm@11979
   652
wenzelm@11979
   653
lemma singleton_insert_inj_eq [iff]: "({b} = insert a A) = (a = b & A <= {b})"
wenzelm@11979
   654
  by blast
wenzelm@11979
   655
wenzelm@11979
   656
lemma singleton_insert_inj_eq' [iff]: "(insert a A = {b}) = (a = b & A <= {b})"
wenzelm@11979
   657
  by blast
wenzelm@11979
   658
wenzelm@11979
   659
lemma subset_singletonD: "A <= {x} ==> A={} | A = {x}"
wenzelm@11979
   660
  by fast
wenzelm@11979
   661
wenzelm@11979
   662
lemma singleton_conv [simp]: "{x. x = a} = {a}"
wenzelm@11979
   663
  by blast
wenzelm@11979
   664
wenzelm@11979
   665
lemma singleton_conv2 [simp]: "{x. a = x} = {a}"
wenzelm@11979
   666
  by blast
clasohm@923
   667
wenzelm@11979
   668
lemma diff_single_insert: "A - {x} <= B ==> x : A ==> A <= insert x B"
wenzelm@11979
   669
  by blast
wenzelm@11979
   670
wenzelm@11979
   671
wenzelm@11979
   672
subsubsection {* Unions of families *}
wenzelm@11979
   673
wenzelm@11979
   674
text {*
wenzelm@11979
   675
  @{term [source] "UN x:A. B x"} is @{term "Union (B`A)"}.
wenzelm@11979
   676
*}
wenzelm@11979
   677
wenzelm@11979
   678
lemma UN_iff [simp]: "(b: (UN x:A. B x)) = (EX x:A. b: B x)"
wenzelm@11979
   679
  by (unfold UNION_def) blast
wenzelm@11979
   680
wenzelm@11979
   681
lemma UN_I [intro]: "a:A ==> b: B a ==> b: (UN x:A. B x)"
wenzelm@11979
   682
  -- {* The order of the premises presupposes that @{term A} is rigid;
wenzelm@11979
   683
    @{term b} may be flexible. *}
wenzelm@11979
   684
  by auto
wenzelm@11979
   685
wenzelm@11979
   686
lemma UN_E [elim!]: "b : (UN x:A. B x) ==> (!!x. x:A ==> b: B x ==> R) ==> R"
wenzelm@11979
   687
  by (unfold UNION_def) blast
clasohm@923
   688
wenzelm@11979
   689
lemma UN_cong [cong]:
wenzelm@11979
   690
    "A = B ==> (!!x. x:B ==> C x = D x) ==> (UN x:A. C x) = (UN x:B. D x)"
wenzelm@11979
   691
  by (simp add: UNION_def)
wenzelm@11979
   692
wenzelm@11979
   693
wenzelm@11979
   694
subsubsection {* Intersections of families *}
wenzelm@11979
   695
wenzelm@11979
   696
text {* @{term [source] "INT x:A. B x"} is @{term "Inter (B`A)"}. *}
wenzelm@11979
   697
wenzelm@11979
   698
lemma INT_iff [simp]: "(b: (INT x:A. B x)) = (ALL x:A. b: B x)"
wenzelm@11979
   699
  by (unfold INTER_def) blast
clasohm@923
   700
wenzelm@11979
   701
lemma INT_I [intro!]: "(!!x. x:A ==> b: B x) ==> b : (INT x:A. B x)"
wenzelm@11979
   702
  by (unfold INTER_def) blast
wenzelm@11979
   703
wenzelm@11979
   704
lemma INT_D [elim]: "b : (INT x:A. B x) ==> a:A ==> b: B a"
wenzelm@11979
   705
  by auto
wenzelm@11979
   706
wenzelm@11979
   707
lemma INT_E [elim]: "b : (INT x:A. B x) ==> (b: B a ==> R) ==> (a~:A ==> R) ==> R"
wenzelm@11979
   708
  -- {* "Classical" elimination -- by the Excluded Middle on @{prop "a:A"}. *}
wenzelm@11979
   709
  by (unfold INTER_def) blast
wenzelm@11979
   710
wenzelm@11979
   711
lemma INT_cong [cong]:
wenzelm@11979
   712
    "A = B ==> (!!x. x:B ==> C x = D x) ==> (INT x:A. C x) = (INT x:B. D x)"
wenzelm@11979
   713
  by (simp add: INTER_def)
wenzelm@7238
   714
clasohm@923
   715
wenzelm@11979
   716
subsubsection {* Union *}
wenzelm@11979
   717
wenzelm@11979
   718
lemma Union_iff [simp]: "(A : Union C) = (EX X:C. A:X)"
wenzelm@11979
   719
  by (unfold Union_def) blast
wenzelm@11979
   720
wenzelm@11979
   721
lemma UnionI [intro]: "X:C ==> A:X ==> A : Union C"
wenzelm@11979
   722
  -- {* The order of the premises presupposes that @{term C} is rigid;
wenzelm@11979
   723
    @{term A} may be flexible. *}
wenzelm@11979
   724
  by auto
wenzelm@11979
   725
wenzelm@11979
   726
lemma UnionE [elim!]: "A : Union C ==> (!!X. A:X ==> X:C ==> R) ==> R"
wenzelm@11979
   727
  by (unfold Union_def) blast
wenzelm@11979
   728
wenzelm@11979
   729
wenzelm@11979
   730
subsubsection {* Inter *}
wenzelm@11979
   731
wenzelm@11979
   732
lemma Inter_iff [simp]: "(A : Inter C) = (ALL X:C. A:X)"
wenzelm@11979
   733
  by (unfold Inter_def) blast
wenzelm@11979
   734
wenzelm@11979
   735
lemma InterI [intro!]: "(!!X. X:C ==> A:X) ==> A : Inter C"
wenzelm@11979
   736
  by (simp add: Inter_def)
wenzelm@11979
   737
wenzelm@11979
   738
text {*
wenzelm@11979
   739
  \medskip A ``destruct'' rule -- every @{term X} in @{term C}
wenzelm@11979
   740
  contains @{term A} as an element, but @{prop "A:X"} can hold when
wenzelm@11979
   741
  @{prop "X:C"} does not!  This rule is analogous to @{text spec}.
wenzelm@11979
   742
*}
wenzelm@11979
   743
wenzelm@11979
   744
lemma InterD [elim]: "A : Inter C ==> X:C ==> A:X"
wenzelm@11979
   745
  by auto
wenzelm@11979
   746
wenzelm@11979
   747
lemma InterE [elim]: "A : Inter C ==> (X~:C ==> R) ==> (A:X ==> R) ==> R"
wenzelm@11979
   748
  -- {* ``Classical'' elimination rule -- does not require proving
wenzelm@11979
   749
    @{prop "X:C"}. *}
wenzelm@11979
   750
  by (unfold Inter_def) blast
wenzelm@11979
   751
wenzelm@11979
   752
text {*
wenzelm@11979
   753
  \medskip Image of a set under a function.  Frequently @{term b} does
wenzelm@11979
   754
  not have the syntactic form of @{term "f x"}.
wenzelm@11979
   755
*}
wenzelm@11979
   756
wenzelm@11979
   757
lemma image_eqI [simp, intro]: "b = f x ==> x:A ==> b : f`A"
wenzelm@11979
   758
  by (unfold image_def) blast
wenzelm@11979
   759
wenzelm@11979
   760
lemma imageI: "x : A ==> f x : f ` A"
wenzelm@11979
   761
  by (rule image_eqI) (rule refl)
wenzelm@11979
   762
wenzelm@11979
   763
lemma rev_image_eqI: "x:A ==> b = f x ==> b : f`A"
wenzelm@11979
   764
  -- {* This version's more effective when we already have the
wenzelm@11979
   765
    required @{term x}. *}
wenzelm@11979
   766
  by (unfold image_def) blast
wenzelm@11979
   767
wenzelm@11979
   768
lemma imageE [elim!]:
wenzelm@11979
   769
  "b : (%x. f x)`A ==> (!!x. b = f x ==> x:A ==> P) ==> P"
wenzelm@11979
   770
  -- {* The eta-expansion gives variable-name preservation. *}
wenzelm@11979
   771
  by (unfold image_def) blast
wenzelm@11979
   772
wenzelm@11979
   773
lemma image_Un: "f`(A Un B) = f`A Un f`B"
wenzelm@11979
   774
  by blast
wenzelm@11979
   775
wenzelm@11979
   776
lemma image_iff: "(z : f`A) = (EX x:A. z = f x)"
wenzelm@11979
   777
  by blast
wenzelm@11979
   778
wenzelm@11979
   779
lemma image_subset_iff: "(f`A <= B) = (ALL x:A. f x: B)"
wenzelm@11979
   780
  -- {* This rewrite rule would confuse users if made default. *}
wenzelm@11979
   781
  by blast
wenzelm@11979
   782
wenzelm@11979
   783
lemma subset_image_iff: "(B <= f ` A) = (EX AA. AA <= A & B = f ` AA)"
wenzelm@11979
   784
  apply safe
wenzelm@11979
   785
   prefer 2 apply fast
wenzelm@11979
   786
  apply (rule_tac x = "{a. a : A & f a : B}" in exI)
wenzelm@11979
   787
  apply fast
wenzelm@11979
   788
  done
wenzelm@11979
   789
wenzelm@11979
   790
lemma image_subsetI: "(!!x. x:A ==> f x : B) ==> f`A <= B"
wenzelm@11979
   791
  -- {* Replaces the three steps @{text subsetI}, @{text imageE},
wenzelm@11979
   792
    @{text hypsubst}, but breaks too many existing proofs. *}
wenzelm@11979
   793
  by blast
wenzelm@11979
   794
wenzelm@11979
   795
text {*
wenzelm@11979
   796
  \medskip Range of a function -- just a translation for image!
wenzelm@11979
   797
*}
wenzelm@11979
   798
wenzelm@11979
   799
lemma range_eqI: "b = f x ==> b : range f"
wenzelm@11979
   800
  by simp
wenzelm@11979
   801
wenzelm@11979
   802
lemma rangeI: "f x : range f"
wenzelm@11979
   803
  by simp
wenzelm@11979
   804
wenzelm@11979
   805
lemma rangeE [elim?]: "b : range (%x. f x) ==> (!!x. b = f x ==> P) ==> P"
wenzelm@11979
   806
  by blast
wenzelm@11979
   807
wenzelm@11979
   808
wenzelm@11979
   809
subsubsection {* Set reasoning tools *}
wenzelm@11979
   810
wenzelm@11979
   811
text {*
wenzelm@11979
   812
  Rewrite rules for boolean case-splitting: faster than @{text
wenzelm@11979
   813
  "split_if [split]"}.
wenzelm@11979
   814
*}
wenzelm@11979
   815
wenzelm@11979
   816
lemma split_if_eq1: "((if Q then x else y) = b) = ((Q --> x = b) & (~ Q --> y = b))"
wenzelm@11979
   817
  by (rule split_if)
wenzelm@11979
   818
wenzelm@11979
   819
lemma split_if_eq2: "(a = (if Q then x else y)) = ((Q --> a = x) & (~ Q --> a = y))"
wenzelm@11979
   820
  by (rule split_if)
wenzelm@11979
   821
wenzelm@11979
   822
text {*
wenzelm@11979
   823
  Split ifs on either side of the membership relation.  Not for @{text
wenzelm@11979
   824
  "[simp]"} -- can cause goals to blow up!
wenzelm@11979
   825
*}
wenzelm@11979
   826
wenzelm@11979
   827
lemma split_if_mem1: "((if Q then x else y) : b) = ((Q --> x : b) & (~ Q --> y : b))"
wenzelm@11979
   828
  by (rule split_if)
wenzelm@11979
   829
wenzelm@11979
   830
lemma split_if_mem2: "(a : (if Q then x else y)) = ((Q --> a : x) & (~ Q --> a : y))"
wenzelm@11979
   831
  by (rule split_if)
wenzelm@11979
   832
wenzelm@11979
   833
lemmas split_ifs = if_bool_eq_conj split_if_eq1 split_if_eq2 split_if_mem1 split_if_mem2
wenzelm@11979
   834
wenzelm@11979
   835
lemmas mem_simps =
wenzelm@11979
   836
  insert_iff empty_iff Un_iff Int_iff Compl_iff Diff_iff
wenzelm@11979
   837
  mem_Collect_eq UN_iff Union_iff INT_iff Inter_iff
wenzelm@11979
   838
  -- {* Each of these has ALREADY been added @{text "[simp]"} above. *}
wenzelm@11979
   839
wenzelm@11979
   840
(*Would like to add these, but the existing code only searches for the
wenzelm@11979
   841
  outer-level constant, which in this case is just "op :"; we instead need
wenzelm@11979
   842
  to use term-nets to associate patterns with rules.  Also, if a rule fails to
wenzelm@11979
   843
  apply, then the formula should be kept.
wenzelm@11979
   844
  [("uminus", Compl_iff RS iffD1), ("op -", [Diff_iff RS iffD1]),
wenzelm@11979
   845
   ("op Int", [IntD1,IntD2]),
wenzelm@11979
   846
   ("Collect", [CollectD]), ("Inter", [InterD]), ("INTER", [INT_D])]
wenzelm@11979
   847
 *)
wenzelm@11979
   848
wenzelm@11979
   849
ML_setup {*
wenzelm@11979
   850
  val mksimps_pairs = [("Ball", [thm "bspec"])] @ mksimps_pairs;
wenzelm@11979
   851
  simpset_ref() := simpset() setmksimps (mksimps mksimps_pairs);
wenzelm@11979
   852
*}
wenzelm@11979
   853
wenzelm@11979
   854
declare subset_UNIV [simp] subset_refl [simp]
wenzelm@11979
   855
wenzelm@11979
   856
wenzelm@11979
   857
subsubsection {* The ``proper subset'' relation *}
wenzelm@11979
   858
wenzelm@11979
   859
lemma psubsetI [intro!]: "(A::'a set) <= B ==> A ~= B ==> A < B"
wenzelm@11979
   860
  by (unfold psubset_def) blast
wenzelm@11979
   861
wenzelm@11979
   862
lemma psubset_insert_iff:
wenzelm@11979
   863
  "(A < insert x B) = (if x:B then A < B else if x:A then A - {x} < B else A <= B)"
wenzelm@11979
   864
  apply (simp add: psubset_def subset_insert_iff)
wenzelm@11979
   865
  apply blast
wenzelm@11979
   866
  done
wenzelm@11979
   867
wenzelm@11979
   868
lemma psubset_eq: "((A::'a set) < B) = (A <= B & A ~= B)"
wenzelm@11979
   869
  by (simp only: psubset_def)
wenzelm@11979
   870
wenzelm@11979
   871
lemma psubset_imp_subset: "(A::'a set) < B ==> A <= B"
wenzelm@11979
   872
  by (simp add: psubset_eq)
wenzelm@11979
   873
wenzelm@11979
   874
lemma psubset_subset_trans: "(A::'a set) < B ==> B <= C ==> A < C"
wenzelm@11979
   875
  by (auto simp add: psubset_eq)
wenzelm@11979
   876
wenzelm@11979
   877
lemma subset_psubset_trans: "(A::'a set) <= B ==> B < C ==> A < C"
wenzelm@11979
   878
  by (auto simp add: psubset_eq)
wenzelm@11979
   879
wenzelm@11979
   880
lemma psubset_imp_ex_mem: "A < B ==> EX b. b : (B - A)"
wenzelm@11979
   881
  by (unfold psubset_def) blast
wenzelm@11979
   882
wenzelm@11979
   883
lemma atomize_ball:
wenzelm@11979
   884
    "(!!x. x:A ==> P x) == Trueprop (ALL x:A. P x)"
wenzelm@11979
   885
  by (simp only: Ball_def atomize_all atomize_imp)
wenzelm@11979
   886
wenzelm@11979
   887
declare atomize_ball [symmetric, rulify]
wenzelm@11979
   888
wenzelm@11979
   889
wenzelm@11979
   890
subsection {* Further set-theory lemmas *}
wenzelm@11979
   891
wenzelm@11979
   892
use "subset.ML"
wenzelm@11979
   893
use "equalities.ML"
wenzelm@11979
   894
use "mono.ML"
wenzelm@11979
   895
wenzelm@11982
   896
lemma Least_mono:
wenzelm@11982
   897
  "mono (f::'a::order => 'b::order) ==> EX x:S. ALL y:S. x <= y
wenzelm@11982
   898
    ==> (LEAST y. y : f ` S) = f (LEAST x. x : S)"
wenzelm@11982
   899
    -- {* Courtesy of Stephan Merz *}
wenzelm@11982
   900
  apply clarify
wenzelm@11982
   901
  apply (erule_tac P = "%x. x : S" in LeastI2)
wenzelm@11982
   902
   apply fast
wenzelm@11982
   903
  apply (rule LeastI2)
wenzelm@11982
   904
  apply (auto elim: monoD intro!: order_antisym)
wenzelm@11982
   905
  done
wenzelm@11982
   906
wenzelm@12020
   907
wenzelm@12020
   908
section {* Transitivity rules for calculational reasoning *}
wenzelm@12020
   909
wenzelm@12020
   910
lemma forw_subst: "a = b ==> P b ==> P a"
wenzelm@12020
   911
  by (rule ssubst)
wenzelm@12020
   912
wenzelm@12020
   913
lemma back_subst: "P a ==> a = b ==> P b"
wenzelm@12020
   914
  by (rule subst)
wenzelm@12020
   915
wenzelm@12020
   916
lemma set_rev_mp: "x:A ==> A <= B ==> x:B"
wenzelm@12020
   917
  by (rule subsetD)
wenzelm@12020
   918
wenzelm@12020
   919
lemma set_mp: "A <= B ==> x:A ==> x:B"
wenzelm@12020
   920
  by (rule subsetD)
wenzelm@12020
   921
wenzelm@12020
   922
lemma order_neq_le_trans: "a ~= b ==> (a::'a::order) <= b ==> a < b"
wenzelm@12020
   923
  by (simp add: order_less_le)
wenzelm@12020
   924
wenzelm@12020
   925
lemma order_le_neq_trans: "(a::'a::order) <= b ==> a ~= b ==> a < b"
wenzelm@12020
   926
  by (simp add: order_less_le)
wenzelm@12020
   927
wenzelm@12020
   928
lemma order_less_asym': "(a::'a::order) < b ==> b < a ==> P"
wenzelm@12020
   929
  by (rule order_less_asym)
wenzelm@12020
   930
wenzelm@12020
   931
lemma ord_le_eq_trans: "a <= b ==> b = c ==> a <= c"
wenzelm@12020
   932
  by (rule subst)
wenzelm@12020
   933
wenzelm@12020
   934
lemma ord_eq_le_trans: "a = b ==> b <= c ==> a <= c"
wenzelm@12020
   935
  by (rule ssubst)
wenzelm@12020
   936
wenzelm@12020
   937
lemma ord_less_eq_trans: "a < b ==> b = c ==> a < c"
wenzelm@12020
   938
  by (rule subst)
wenzelm@12020
   939
wenzelm@12020
   940
lemma ord_eq_less_trans: "a = b ==> b < c ==> a < c"
wenzelm@12020
   941
  by (rule ssubst)
wenzelm@12020
   942
wenzelm@12020
   943
lemma order_less_subst2: "(a::'a::order) < b ==> f b < (c::'c::order) ==>
wenzelm@12020
   944
  (!!x y. x < y ==> f x < f y) ==> f a < c"
wenzelm@12020
   945
proof -
wenzelm@12020
   946
  assume r: "!!x y. x < y ==> f x < f y"
wenzelm@12020
   947
  assume "a < b" hence "f a < f b" by (rule r)
wenzelm@12020
   948
  also assume "f b < c"
wenzelm@12020
   949
  finally (order_less_trans) show ?thesis .
wenzelm@12020
   950
qed
wenzelm@12020
   951
wenzelm@12020
   952
lemma order_less_subst1: "(a::'a::order) < f b ==> (b::'b::order) < c ==>
wenzelm@12020
   953
  (!!x y. x < y ==> f x < f y) ==> a < f c"
wenzelm@12020
   954
proof -
wenzelm@12020
   955
  assume r: "!!x y. x < y ==> f x < f y"
wenzelm@12020
   956
  assume "a < f b"
wenzelm@12020
   957
  also assume "b < c" hence "f b < f c" by (rule r)
wenzelm@12020
   958
  finally (order_less_trans) show ?thesis .
wenzelm@12020
   959
qed
wenzelm@12020
   960
wenzelm@12020
   961
lemma order_le_less_subst2: "(a::'a::order) <= b ==> f b < (c::'c::order) ==>
wenzelm@12020
   962
  (!!x y. x <= y ==> f x <= f y) ==> f a < c"
wenzelm@12020
   963
proof -
wenzelm@12020
   964
  assume r: "!!x y. x <= y ==> f x <= f y"
wenzelm@12020
   965
  assume "a <= b" hence "f a <= f b" by (rule r)
wenzelm@12020
   966
  also assume "f b < c"
wenzelm@12020
   967
  finally (order_le_less_trans) show ?thesis .
wenzelm@12020
   968
qed
wenzelm@12020
   969
wenzelm@12020
   970
lemma order_le_less_subst1: "(a::'a::order) <= f b ==> (b::'b::order) < c ==>
wenzelm@12020
   971
  (!!x y. x < y ==> f x < f y) ==> a < f c"
wenzelm@12020
   972
proof -
wenzelm@12020
   973
  assume r: "!!x y. x < y ==> f x < f y"
wenzelm@12020
   974
  assume "a <= f b"
wenzelm@12020
   975
  also assume "b < c" hence "f b < f c" by (rule r)
wenzelm@12020
   976
  finally (order_le_less_trans) show ?thesis .
wenzelm@12020
   977
qed
wenzelm@12020
   978
wenzelm@12020
   979
lemma order_less_le_subst2: "(a::'a::order) < b ==> f b <= (c::'c::order) ==>
wenzelm@12020
   980
  (!!x y. x < y ==> f x < f y) ==> f a < c"
wenzelm@12020
   981
proof -
wenzelm@12020
   982
  assume r: "!!x y. x < y ==> f x < f y"
wenzelm@12020
   983
  assume "a < b" hence "f a < f b" by (rule r)
wenzelm@12020
   984
  also assume "f b <= c"
wenzelm@12020
   985
  finally (order_less_le_trans) show ?thesis .
wenzelm@12020
   986
qed
wenzelm@12020
   987
wenzelm@12020
   988
lemma order_less_le_subst1: "(a::'a::order) < f b ==> (b::'b::order) <= c ==>
wenzelm@12020
   989
  (!!x y. x <= y ==> f x <= f y) ==> a < f c"
wenzelm@12020
   990
proof -
wenzelm@12020
   991
  assume r: "!!x y. x <= y ==> f x <= f y"
wenzelm@12020
   992
  assume "a < f b"
wenzelm@12020
   993
  also assume "b <= c" hence "f b <= f c" by (rule r)
wenzelm@12020
   994
  finally (order_less_le_trans) show ?thesis .
wenzelm@12020
   995
qed
wenzelm@12020
   996
wenzelm@12020
   997
lemma order_subst1: "(a::'a::order) <= f b ==> (b::'b::order) <= c ==>
wenzelm@12020
   998
  (!!x y. x <= y ==> f x <= f y) ==> a <= f c"
wenzelm@12020
   999
proof -
wenzelm@12020
  1000
  assume r: "!!x y. x <= y ==> f x <= f y"
wenzelm@12020
  1001
  assume "a <= f b"
wenzelm@12020
  1002
  also assume "b <= c" hence "f b <= f c" by (rule r)
wenzelm@12020
  1003
  finally (order_trans) show ?thesis .
wenzelm@12020
  1004
qed
wenzelm@12020
  1005
wenzelm@12020
  1006
lemma order_subst2: "(a::'a::order) <= b ==> f b <= (c::'c::order) ==>
wenzelm@12020
  1007
  (!!x y. x <= y ==> f x <= f y) ==> f a <= c"
wenzelm@12020
  1008
proof -
wenzelm@12020
  1009
  assume r: "!!x y. x <= y ==> f x <= f y"
wenzelm@12020
  1010
  assume "a <= b" hence "f a <= f b" by (rule r)
wenzelm@12020
  1011
  also assume "f b <= c"
wenzelm@12020
  1012
  finally (order_trans) show ?thesis .
wenzelm@12020
  1013
qed
wenzelm@12020
  1014
wenzelm@12020
  1015
lemma ord_le_eq_subst: "a <= b ==> f b = c ==>
wenzelm@12020
  1016
  (!!x y. x <= y ==> f x <= f y) ==> f a <= c"
wenzelm@12020
  1017
proof -
wenzelm@12020
  1018
  assume r: "!!x y. x <= y ==> f x <= f y"
wenzelm@12020
  1019
  assume "a <= b" hence "f a <= f b" by (rule r)
wenzelm@12020
  1020
  also assume "f b = c"
wenzelm@12020
  1021
  finally (ord_le_eq_trans) show ?thesis .
wenzelm@12020
  1022
qed
wenzelm@12020
  1023
wenzelm@12020
  1024
lemma ord_eq_le_subst: "a = f b ==> b <= c ==>
wenzelm@12020
  1025
  (!!x y. x <= y ==> f x <= f y) ==> a <= f c"
wenzelm@12020
  1026
proof -
wenzelm@12020
  1027
  assume r: "!!x y. x <= y ==> f x <= f y"
wenzelm@12020
  1028
  assume "a = f b"
wenzelm@12020
  1029
  also assume "b <= c" hence "f b <= f c" by (rule r)
wenzelm@12020
  1030
  finally (ord_eq_le_trans) show ?thesis .
wenzelm@12020
  1031
qed
wenzelm@12020
  1032
wenzelm@12020
  1033
lemma ord_less_eq_subst: "a < b ==> f b = c ==>
wenzelm@12020
  1034
  (!!x y. x < y ==> f x < f y) ==> f a < c"
wenzelm@12020
  1035
proof -
wenzelm@12020
  1036
  assume r: "!!x y. x < y ==> f x < f y"
wenzelm@12020
  1037
  assume "a < b" hence "f a < f b" by (rule r)
wenzelm@12020
  1038
  also assume "f b = c"
wenzelm@12020
  1039
  finally (ord_less_eq_trans) show ?thesis .
wenzelm@12020
  1040
qed
wenzelm@12020
  1041
wenzelm@12020
  1042
lemma ord_eq_less_subst: "a = f b ==> b < c ==>
wenzelm@12020
  1043
  (!!x y. x < y ==> f x < f y) ==> a < f c"
wenzelm@12020
  1044
proof -
wenzelm@12020
  1045
  assume r: "!!x y. x < y ==> f x < f y"
wenzelm@12020
  1046
  assume "a = f b"
wenzelm@12020
  1047
  also assume "b < c" hence "f b < f c" by (rule r)
wenzelm@12020
  1048
  finally (ord_eq_less_trans) show ?thesis .
wenzelm@12020
  1049
qed
wenzelm@12020
  1050
wenzelm@12020
  1051
text {*
wenzelm@12020
  1052
  Note that this list of rules is in reverse order of priorities.
wenzelm@12020
  1053
*}
wenzelm@12020
  1054
wenzelm@12020
  1055
lemmas basic_trans_rules [trans] =
wenzelm@12020
  1056
  order_less_subst2
wenzelm@12020
  1057
  order_less_subst1
wenzelm@12020
  1058
  order_le_less_subst2
wenzelm@12020
  1059
  order_le_less_subst1
wenzelm@12020
  1060
  order_less_le_subst2
wenzelm@12020
  1061
  order_less_le_subst1
wenzelm@12020
  1062
  order_subst2
wenzelm@12020
  1063
  order_subst1
wenzelm@12020
  1064
  ord_le_eq_subst
wenzelm@12020
  1065
  ord_eq_le_subst
wenzelm@12020
  1066
  ord_less_eq_subst
wenzelm@12020
  1067
  ord_eq_less_subst
wenzelm@12020
  1068
  forw_subst
wenzelm@12020
  1069
  back_subst
wenzelm@12020
  1070
  rev_mp
wenzelm@12020
  1071
  mp
wenzelm@12020
  1072
  set_rev_mp
wenzelm@12020
  1073
  set_mp
wenzelm@12020
  1074
  order_neq_le_trans
wenzelm@12020
  1075
  order_le_neq_trans
wenzelm@12020
  1076
  order_less_trans
wenzelm@12020
  1077
  order_less_asym'
wenzelm@12020
  1078
  order_le_less_trans
wenzelm@12020
  1079
  order_less_le_trans
wenzelm@12020
  1080
  order_trans
wenzelm@12020
  1081
  order_antisym
wenzelm@12020
  1082
  ord_le_eq_trans
wenzelm@12020
  1083
  ord_eq_le_trans
wenzelm@12020
  1084
  ord_less_eq_trans
wenzelm@12020
  1085
  ord_eq_less_trans
wenzelm@12020
  1086
  trans
wenzelm@12020
  1087
wenzelm@11979
  1088
end