diff --git a/src/HOL/Fun.thy b/src/HOL/Fun.thy
--- a/src/HOL/Fun.thy
+++ b/src/HOL/Fun.thy
@@ -1,1076 +1,1108 @@
 (*  Title:      HOL/Fun.thy
     Author:     Tobias Nipkow, Cambridge University Computer Laboratory
     Author:     Andrei Popescu, TU Muenchen
     Copyright   1994, 2012
 *)
 
 section \<open>Notions about functions\<close>
 
 theory Fun
   imports Set
   keywords "functor" :: thy_goal_defn
 begin
 
 lemma apply_inverse: "f x = u \<Longrightarrow> (\<And>x. P x \<Longrightarrow> g (f x) = x) \<Longrightarrow> P x \<Longrightarrow> x = g u"
   by auto
 
 text \<open>Uniqueness, so NOT the axiom of choice.\<close>
 lemma uniq_choice: "\<forall>x. \<exists>!y. Q x y \<Longrightarrow> \<exists>f. \<forall>x. Q x (f x)"
   by (force intro: theI')
 
 lemma b_uniq_choice: "\<forall>x\<in>S. \<exists>!y. Q x y \<Longrightarrow> \<exists>f. \<forall>x\<in>S. Q x (f x)"
   by (force intro: theI')
 
 
 subsection \<open>The Identity Function \<open>id\<close>\<close>
 
 definition id :: "'a \<Rightarrow> 'a"
   where "id = (\<lambda>x. x)"
 
 lemma id_apply [simp]: "id x = x"
   by (simp add: id_def)
 
 lemma image_id [simp]: "image id = id"
   by (simp add: id_def fun_eq_iff)
 
 lemma vimage_id [simp]: "vimage id = id"
   by (simp add: id_def fun_eq_iff)
 
 lemma eq_id_iff: "(\<forall>x. f x = x) \<longleftrightarrow> f = id"
   by auto
 
 code_printing
   constant id \<rightharpoonup> (Haskell) "id"
 
 
 subsection \<open>The Composition Operator \<open>f \<circ> g\<close>\<close>
 
 definition comp :: "('b \<Rightarrow> 'c) \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'a \<Rightarrow> 'c"  (infixl "\<circ>" 55)
   where "f \<circ> g = (\<lambda>x. f (g x))"
 
 notation (ASCII)
   comp  (infixl "o" 55)
 
 lemma comp_apply [simp]: "(f \<circ> g) x = f (g x)"
   by (simp add: comp_def)
 
 lemma comp_assoc: "(f \<circ> g) \<circ> h = f \<circ> (g \<circ> h)"
   by (simp add: fun_eq_iff)
 
 lemma id_comp [simp]: "id \<circ> g = g"
   by (simp add: fun_eq_iff)
 
 lemma comp_id [simp]: "f \<circ> id = f"
   by (simp add: fun_eq_iff)
 
 lemma comp_eq_dest: "a \<circ> b = c \<circ> d \<Longrightarrow> a (b v) = c (d v)"
   by (simp add: fun_eq_iff)
 
 lemma comp_eq_elim: "a \<circ> b = c \<circ> d \<Longrightarrow> ((\<And>v. a (b v) = c (d v)) \<Longrightarrow> R) \<Longrightarrow> R"
   by (simp add: fun_eq_iff)
 
 lemma comp_eq_dest_lhs: "a \<circ> b = c \<Longrightarrow> a (b v) = c v"
   by clarsimp
 
 lemma comp_eq_id_dest: "a \<circ> b = id \<circ> c \<Longrightarrow> a (b v) = c v"
   by clarsimp
 
 lemma image_comp: "f ` (g ` r) = (f \<circ> g) ` r"
   by auto
 
 lemma vimage_comp: "f -` (g -` x) = (g \<circ> f) -` x"
   by auto
 
 lemma image_eq_imp_comp: "f ` A = g ` B \<Longrightarrow> (h \<circ> f) ` A = (h \<circ> g) ` B"
   by (auto simp: comp_def elim!: equalityE)
 
 lemma image_bind: "f ` (Set.bind A g) = Set.bind A ((`) f \<circ> g)"
   by (auto simp add: Set.bind_def)
 
 lemma bind_image: "Set.bind (f ` A) g = Set.bind A (g \<circ> f)"
   by (auto simp add: Set.bind_def)
 
 lemma (in group_add) minus_comp_minus [simp]: "uminus \<circ> uminus = id"
   by (simp add: fun_eq_iff)
 
 lemma (in boolean_algebra) minus_comp_minus [simp]: "uminus \<circ> uminus = id"
   by (simp add: fun_eq_iff)
 
 code_printing
   constant comp \<rightharpoonup> (SML) infixl 5 "o" and (Haskell) infixr 9 "."
 
 
 subsection \<open>The Forward Composition Operator \<open>fcomp\<close>\<close>
 
 definition fcomp :: "('a \<Rightarrow> 'b) \<Rightarrow> ('b \<Rightarrow> 'c) \<Rightarrow> 'a \<Rightarrow> 'c"  (infixl "\<circ>>" 60)
   where "f \<circ>> g = (\<lambda>x. g (f x))"
 
 lemma fcomp_apply [simp]:  "(f \<circ>> g) x = g (f x)"
   by (simp add: fcomp_def)
 
 lemma fcomp_assoc: "(f \<circ>> g) \<circ>> h = f \<circ>> (g \<circ>> h)"
   by (simp add: fcomp_def)
 
 lemma id_fcomp [simp]: "id \<circ>> g = g"
   by (simp add: fcomp_def)
 
 lemma fcomp_id [simp]: "f \<circ>> id = f"
   by (simp add: fcomp_def)
 
 lemma fcomp_comp: "fcomp f g = comp g f"
   by (simp add: ext)
 
 code_printing
   constant fcomp \<rightharpoonup> (Eval) infixl 1 "#>"
 
 no_notation fcomp (infixl "\<circ>>" 60)
 
 
 subsection \<open>Mapping functions\<close>
 
 definition map_fun :: "('c \<Rightarrow> 'a) \<Rightarrow> ('b \<Rightarrow> 'd) \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'c \<Rightarrow> 'd"
   where "map_fun f g h = g \<circ> h \<circ> f"
 
 lemma map_fun_apply [simp]: "map_fun f g h x = g (h (f x))"
   by (simp add: map_fun_def)
 
 
 subsection \<open>Injectivity and Bijectivity\<close>
 
 definition inj_on :: "('a \<Rightarrow> 'b) \<Rightarrow> 'a set \<Rightarrow> bool"  \<comment> \<open>injective\<close>
   where "inj_on f A \<longleftrightarrow> (\<forall>x\<in>A. \<forall>y\<in>A. f x = f y \<longrightarrow> x = y)"
 
 definition bij_betw :: "('a \<Rightarrow> 'b) \<Rightarrow> 'a set \<Rightarrow> 'b set \<Rightarrow> bool"  \<comment> \<open>bijective\<close>
   where "bij_betw f A B \<longleftrightarrow> inj_on f A \<and> f ` A = B"
 
 text \<open>
   A common special case: functions injective, surjective or bijective over
   the entire domain type.
 \<close>
 
 abbreviation inj :: "('a \<Rightarrow> 'b) \<Rightarrow> bool"
   where "inj f \<equiv> inj_on f UNIV"
 
 abbreviation surj :: "('a \<Rightarrow> 'b) \<Rightarrow> bool"
   where "surj f \<equiv> range f = UNIV"
 
 translations \<comment> \<open>The negated case:\<close>
   "\<not> CONST surj f" \<leftharpoondown> "CONST range f \<noteq> CONST UNIV"
 
 abbreviation bij :: "('a \<Rightarrow> 'b) \<Rightarrow> bool"
   where "bij f \<equiv> bij_betw f UNIV UNIV"
 
 lemma inj_def: "inj f \<longleftrightarrow> (\<forall>x y. f x = f y \<longrightarrow> x = y)"
   unfolding inj_on_def by blast
 
 lemma injI: "(\<And>x y. f x = f y \<Longrightarrow> x = y) \<Longrightarrow> inj f"
   unfolding inj_def by blast
 
 theorem range_ex1_eq: "inj f \<Longrightarrow> b \<in> range f \<longleftrightarrow> (\<exists>!x. b = f x)"
   unfolding inj_def by blast
 
 lemma injD: "inj f \<Longrightarrow> f x = f y \<Longrightarrow> x = y"
   by (simp add: inj_def)
 
 lemma inj_on_eq_iff: "inj_on f A \<Longrightarrow> x \<in> A \<Longrightarrow> y \<in> A \<Longrightarrow> f x = f y \<longleftrightarrow> x = y"
   by (auto simp: inj_on_def)
 
 lemma inj_on_cong: "(\<And>a. a \<in> A \<Longrightarrow> f a = g a) \<Longrightarrow> inj_on f A \<longleftrightarrow> inj_on g A"
   by (auto simp: inj_on_def)
 
 lemma inj_on_strict_subset: "inj_on f B \<Longrightarrow> A \<subset> B \<Longrightarrow> f ` A \<subset> f ` B"
   unfolding inj_on_def by blast
 
 lemma inj_compose: "inj f \<Longrightarrow> inj g \<Longrightarrow> inj (f \<circ> g)"
   by (simp add: inj_def)
 
 lemma inj_fun: "inj f \<Longrightarrow> inj (\<lambda>x y. f x)"
   by (simp add: inj_def fun_eq_iff)
 
 lemma inj_eq: "inj f \<Longrightarrow> f x = f y \<longleftrightarrow> x = y"
   by (simp add: inj_on_eq_iff)
 
 lemma inj_on_iff_Uniq: "inj_on f A \<longleftrightarrow> (\<forall>x\<in>A. \<exists>\<^sub>\<le>\<^sub>1y. y\<in>A \<and> f x = f y)"
   by (auto simp: Uniq_def inj_on_def)
 
 lemma inj_on_id[simp]: "inj_on id A"
   by (simp add: inj_on_def)
 
 lemma inj_on_id2[simp]: "inj_on (\<lambda>x. x) A"
   by (simp add: inj_on_def)
 
 lemma inj_on_Int: "inj_on f A \<or> inj_on f B \<Longrightarrow> inj_on f (A \<inter> B)"
   unfolding inj_on_def by blast
 
 lemma surj_id: "surj id"
   by simp
 
 lemma bij_id[simp]: "bij id"
   by (simp add: bij_betw_def)
 
 lemma bij_uminus: "bij (uminus :: 'a \<Rightarrow> 'a::ab_group_add)"
   unfolding bij_betw_def inj_on_def
   by (force intro: minus_minus [symmetric])
 
 lemma bij_betwE: "bij_betw f A B \<Longrightarrow> \<forall>a\<in>A. f a \<in> B"
   unfolding bij_betw_def by auto
 
 lemma inj_onI [intro?]: "(\<And>x y. x \<in> A \<Longrightarrow> y \<in> A \<Longrightarrow> f x = f y \<Longrightarrow> x = y) \<Longrightarrow> inj_on f A"
   by (simp add: inj_on_def)
 
 lemma inj_on_inverseI: "(\<And>x. x \<in> A \<Longrightarrow> g (f x) = x) \<Longrightarrow> inj_on f A"
   by (auto dest: arg_cong [of concl: g] simp add: inj_on_def)
 
 lemma inj_onD: "inj_on f A \<Longrightarrow> f x = f y \<Longrightarrow> x \<in> A \<Longrightarrow> y \<in> A \<Longrightarrow> x = y"
   unfolding inj_on_def by blast
 
 lemma inj_on_subset:
   assumes "inj_on f A"
     and "B \<subseteq> A"
   shows "inj_on f B"
 proof (rule inj_onI)
   fix a b
   assume "a \<in> B" and "b \<in> B"
   with assms have "a \<in> A" and "b \<in> A"
     by auto
   moreover assume "f a = f b"
   ultimately show "a = b"
     using assms by (auto dest: inj_onD)
 qed
 
 lemma comp_inj_on: "inj_on f A \<Longrightarrow> inj_on g (f ` A) \<Longrightarrow> inj_on (g \<circ> f) A"
   by (simp add: comp_def inj_on_def)
 
 lemma inj_on_imageI: "inj_on (g \<circ> f) A \<Longrightarrow> inj_on g (f ` A)"
   by (auto simp add: inj_on_def)
 
 lemma inj_on_image_iff:
   "\<forall>x\<in>A. \<forall>y\<in>A. g (f x) = g (f y) \<longleftrightarrow> g x = g y \<Longrightarrow> inj_on f A \<Longrightarrow> inj_on g (f ` A) \<longleftrightarrow> inj_on g A"
   unfolding inj_on_def by blast
 
 lemma inj_on_contraD: "inj_on f A \<Longrightarrow> x \<noteq> y \<Longrightarrow> x \<in> A \<Longrightarrow> y \<in> A \<Longrightarrow> f x \<noteq> f y"
   unfolding inj_on_def by blast
 
 lemma inj_singleton [simp]: "inj_on (\<lambda>x. {x}) A"
   by (simp add: inj_on_def)
 
 lemma inj_on_empty[iff]: "inj_on f {}"
   by (simp add: inj_on_def)
 
 lemma subset_inj_on: "inj_on f B \<Longrightarrow> A \<subseteq> B \<Longrightarrow> inj_on f A"
   unfolding inj_on_def by blast
 
 lemma inj_on_Un: "inj_on f (A \<union> B) \<longleftrightarrow> inj_on f A \<and> inj_on f B \<and> f ` (A - B) \<inter> f ` (B - A) = {}"
   unfolding inj_on_def by (blast intro: sym)
 
 lemma inj_on_insert [iff]: "inj_on f (insert a A) \<longleftrightarrow> inj_on f A \<and> f a \<notin> f ` (A - {a})"
   unfolding inj_on_def by (blast intro: sym)
 
 lemma inj_on_diff: "inj_on f A \<Longrightarrow> inj_on f (A - B)"
   unfolding inj_on_def by blast
 
 lemma comp_inj_on_iff: "inj_on f A \<Longrightarrow> inj_on f' (f ` A) \<longleftrightarrow> inj_on (f' \<circ> f) A"
   by (auto simp: comp_inj_on inj_on_def)
 
 lemma inj_on_imageI2: "inj_on (f' \<circ> f) A \<Longrightarrow> inj_on f A"
   by (auto simp: comp_inj_on inj_on_def)
 
 lemma inj_img_insertE:
   assumes "inj_on f A"
   assumes "x \<notin> B"
     and "insert x B = f ` A"
   obtains x' A' where "x' \<notin> A'" and "A = insert x' A'" and "x = f x'" and "B = f ` A'"
 proof -
   from assms have "x \<in> f ` A" by auto
   then obtain x' where *: "x' \<in> A" "x = f x'" by auto
   then have A: "A = insert x' (A - {x'})" by auto
   with assms * have B: "B = f ` (A - {x'})" by (auto dest: inj_on_contraD)
   have "x' \<notin> A - {x'}" by simp
   from this A \<open>x = f x'\<close> B show ?thesis ..
 qed
 
 lemma linorder_inj_onI:
   fixes A :: "'a::order set"
   assumes ne: "\<And>x y. \<lbrakk>x < y; x\<in>A; y\<in>A\<rbrakk> \<Longrightarrow> f x \<noteq> f y" and lin: "\<And>x y. \<lbrakk>x\<in>A; y\<in>A\<rbrakk> \<Longrightarrow> x\<le>y \<or> y\<le>x"
   shows "inj_on f A"
 proof (rule inj_onI)
   fix x y
   assume eq: "f x = f y" and "x\<in>A" "y\<in>A"
   then show "x = y"
     using lin [of x y] ne by (force simp: dual_order.order_iff_strict)
 qed
 
 lemma linorder_injI:
   assumes "\<And>x y::'a::linorder. x < y \<Longrightarrow> f x \<noteq> f y"
   shows "inj f"
     \<comment> \<open>Courtesy of Stephan Merz\<close>
 using assms by (auto intro: linorder_inj_onI linear)
 
 lemma inj_on_image_Pow: "inj_on f A \<Longrightarrow>inj_on (image f) (Pow A)"
   unfolding Pow_def inj_on_def by blast
 
 lemma bij_betw_image_Pow: "bij_betw f A B \<Longrightarrow> bij_betw (image f) (Pow A) (Pow B)"
   by (auto simp add: bij_betw_def inj_on_image_Pow image_Pow_surj)
 
 lemma surj_def: "surj f \<longleftrightarrow> (\<forall>y. \<exists>x. y = f x)"
   by auto
 
 lemma surjI:
   assumes "\<And>x. g (f x) = x"
   shows "surj g"
   using assms [symmetric] by auto
 
 lemma surjD: "surj f \<Longrightarrow> \<exists>x. y = f x"
   by (simp add: surj_def)
 
 lemma surjE: "surj f \<Longrightarrow> (\<And>x. y = f x \<Longrightarrow> C) \<Longrightarrow> C"
   by (simp add: surj_def) blast
 
 lemma comp_surj: "surj f \<Longrightarrow> surj g \<Longrightarrow> surj (g \<circ> f)"
   using image_comp [of g f UNIV] by simp
 
 lemma bij_betw_imageI: "inj_on f A \<Longrightarrow> f ` A = B \<Longrightarrow> bij_betw f A B"
   unfolding bij_betw_def by clarify
 
 lemma bij_betw_imp_surj_on: "bij_betw f A B \<Longrightarrow> f ` A = B"
   unfolding bij_betw_def by clarify
 
 lemma bij_betw_imp_surj: "bij_betw f A UNIV \<Longrightarrow> surj f"
   unfolding bij_betw_def by auto
 
 lemma bij_betw_empty1: "bij_betw f {} A \<Longrightarrow> A = {}"
   unfolding bij_betw_def by blast
 
 lemma bij_betw_empty2: "bij_betw f A {} \<Longrightarrow> A = {}"
   unfolding bij_betw_def by blast
 
 lemma inj_on_imp_bij_betw: "inj_on f A \<Longrightarrow> bij_betw f A (f ` A)"
   unfolding bij_betw_def by simp
 
 lemma bij_betw_apply: "\<lbrakk>bij_betw f A B; a \<in> A\<rbrakk> \<Longrightarrow> f a \<in> B"
   unfolding bij_betw_def by auto
 
 lemma bij_def: "bij f \<longleftrightarrow> inj f \<and> surj f"
   by (rule bij_betw_def)
 
 lemma bijI: "inj f \<Longrightarrow> surj f \<Longrightarrow> bij f"
   by (rule bij_betw_imageI)
 
 lemma bij_is_inj: "bij f \<Longrightarrow> inj f"
   by (simp add: bij_def)
 
 lemma bij_is_surj: "bij f \<Longrightarrow> surj f"
   by (simp add: bij_def)
 
 lemma bij_betw_imp_inj_on: "bij_betw f A B \<Longrightarrow> inj_on f A"
   by (simp add: bij_betw_def)
 
 lemma bij_betw_trans: "bij_betw f A B \<Longrightarrow> bij_betw g B C \<Longrightarrow> bij_betw (g \<circ> f) A C"
   by (auto simp add:bij_betw_def comp_inj_on)
 
 lemma bij_comp: "bij f \<Longrightarrow> bij g \<Longrightarrow> bij (g \<circ> f)"
   by (rule bij_betw_trans)
 
 lemma bij_betw_comp_iff: "bij_betw f A A' \<Longrightarrow> bij_betw f' A' A'' \<longleftrightarrow> bij_betw (f' \<circ> f) A A''"
   by (auto simp add: bij_betw_def inj_on_def)
 
 lemma bij_betw_comp_iff2:
   assumes bij: "bij_betw f' A' A''"
     and img: "f ` A \<le> A'"
   shows "bij_betw f A A' \<longleftrightarrow> bij_betw (f' \<circ> f) A A''"
   using assms
 proof (auto simp add: bij_betw_comp_iff)
   assume *: "bij_betw (f' \<circ> f) A A''"
   then show "bij_betw f A A'"
     using img
   proof (auto simp add: bij_betw_def)
     assume "inj_on (f' \<circ> f) A"
     then show "inj_on f A"
       using inj_on_imageI2 by blast
   next
     fix a'
     assume **: "a' \<in> A'"
     with bij have "f' a' \<in> A''"
       unfolding bij_betw_def by auto
     with * obtain a where 1: "a \<in> A \<and> f' (f a) = f' a'"
       unfolding bij_betw_def by force
     with img have "f a \<in> A'" by auto
     with bij ** 1 have "f a = a'"
       unfolding bij_betw_def inj_on_def by auto
     with 1 show "a' \<in> f ` A" by auto
   qed
 qed
 
 lemma bij_betw_inv:
   assumes "bij_betw f A B"
   shows "\<exists>g. bij_betw g B A"
 proof -
   have i: "inj_on f A" and s: "f ` A = B"
     using assms by (auto simp: bij_betw_def)
   let ?P = "\<lambda>b a. a \<in> A \<and> f a = b"
   let ?g = "\<lambda>b. The (?P b)"
   have g: "?g b = a" if P: "?P b a" for a b
   proof -
     from that s have ex1: "\<exists>a. ?P b a" by blast
     then have uex1: "\<exists>!a. ?P b a" by (blast dest:inj_onD[OF i])
     then show ?thesis
       using the1_equality[OF uex1, OF P] P by simp
   qed
   have "inj_on ?g B"
   proof (rule inj_onI)
     fix x y
     assume "x \<in> B" "y \<in> B" "?g x = ?g y"
     from s \<open>x \<in> B\<close> obtain a1 where a1: "?P x a1" by blast
     from s \<open>y \<in> B\<close> obtain a2 where a2: "?P y a2" by blast
     from g [OF a1] a1 g [OF a2] a2 \<open>?g x = ?g y\<close> show "x = y" by simp
   qed
   moreover have "?g ` B = A"
   proof (auto simp: image_def)
     fix b
     assume "b \<in> B"
     with s obtain a where P: "?P b a" by blast
     with g[OF P] show "?g b \<in> A" by auto
   next
     fix a
     assume "a \<in> A"
     with s obtain b where P: "?P b a" by blast
     with s have "b \<in> B" by blast
     with g[OF P] show "\<exists>b\<in>B. a = ?g b" by blast
   qed
   ultimately show ?thesis
     by (auto simp: bij_betw_def)
 qed
 
 lemma bij_betw_cong: "(\<And>a. a \<in> A \<Longrightarrow> f a = g a) \<Longrightarrow> bij_betw f A A' = bij_betw g A A'"
   unfolding bij_betw_def inj_on_def by safe force+  (* somewhat slow *)
 
 lemma bij_betw_id[intro, simp]: "bij_betw id A A"
   unfolding bij_betw_def id_def by auto
 
 lemma bij_betw_id_iff: "bij_betw id A B \<longleftrightarrow> A = B"
   by (auto simp add: bij_betw_def)
 
 lemma bij_betw_combine:
   "bij_betw f A B \<Longrightarrow> bij_betw f C D \<Longrightarrow> B \<inter> D = {} \<Longrightarrow> bij_betw f (A \<union> C) (B \<union> D)"
   unfolding bij_betw_def inj_on_Un image_Un by auto
 
 lemma bij_betw_subset: "bij_betw f A A' \<Longrightarrow> B \<subseteq> A \<Longrightarrow> f ` B = B' \<Longrightarrow> bij_betw f B B'"
   by (auto simp add: bij_betw_def inj_on_def)
 
 lemma bij_pointE:
   assumes "bij f"
   obtains x where "y = f x" and "\<And>x'. y = f x' \<Longrightarrow> x' = x"
 proof -
   from assms have "inj f" by (rule bij_is_inj)
   moreover from assms have "surj f" by (rule bij_is_surj)
   then have "y \<in> range f" by simp
   ultimately have "\<exists>!x. y = f x" by (simp add: range_ex1_eq)
   with that show thesis by blast
 qed
 
+lemma bij_iff: \<^marker>\<open>contributor \<open>Amine Chaieb\<close>\<close>
+  \<open>bij f \<longleftrightarrow> (\<forall>x. \<exists>!y. f y = x)\<close>  (is \<open>?P \<longleftrightarrow> ?Q\<close>)
+proof
+  assume ?P
+  then have \<open>inj f\<close> \<open>surj f\<close>
+    by (simp_all add: bij_def)
+  show ?Q
+  proof
+    fix y
+    from \<open>surj f\<close> obtain x where \<open>y = f x\<close>
+      by (auto simp add: surj_def)
+    with \<open>inj f\<close> show \<open>\<exists>!x. f x = y\<close>
+      by (auto simp add: inj_def)
+  qed
+next
+  assume ?Q
+  then have \<open>inj f\<close>
+    by (auto simp add: inj_def)
+  moreover have \<open>\<exists>x. y = f x\<close> for y
+  proof -
+    from \<open>?Q\<close> obtain x where \<open>f x = y\<close>
+      by blast
+    then have \<open>y = f x\<close>
+      by simp
+    then show ?thesis ..
+  qed
+  then have \<open>surj f\<close>
+    by (auto simp add: surj_def)
+  ultimately show ?P
+    by (rule bijI)
+qed
+
 lemma surj_image_vimage_eq: "surj f \<Longrightarrow> f ` (f -` A) = A"
   by simp
 
 lemma surj_vimage_empty:
   assumes "surj f"
   shows "f -` A = {} \<longleftrightarrow> A = {}"
   using surj_image_vimage_eq [OF \<open>surj f\<close>, of A]
   by (intro iffI) fastforce+
 
 lemma inj_vimage_image_eq: "inj f \<Longrightarrow> f -` (f ` A) = A"
   unfolding inj_def by blast
 
 lemma vimage_subsetD: "surj f \<Longrightarrow> f -` B \<subseteq> A \<Longrightarrow> B \<subseteq> f ` A"
   by (blast intro: sym)
 
 lemma vimage_subsetI: "inj f \<Longrightarrow> B \<subseteq> f ` A \<Longrightarrow> f -` B \<subseteq> A"
   unfolding inj_def by blast
 
 lemma vimage_subset_eq: "bij f \<Longrightarrow> f -` B \<subseteq> A \<longleftrightarrow> B \<subseteq> f ` A"
   unfolding bij_def by (blast del: subsetI intro: vimage_subsetI vimage_subsetD)
 
 lemma inj_on_image_eq_iff: "inj_on f C \<Longrightarrow> A \<subseteq> C \<Longrightarrow> B \<subseteq> C \<Longrightarrow> f ` A = f ` B \<longleftrightarrow> A = B"
   by (fastforce simp: inj_on_def)
 
 lemma inj_on_Un_image_eq_iff: "inj_on f (A \<union> B) \<Longrightarrow> f ` A = f ` B \<longleftrightarrow> A = B"
   by (erule inj_on_image_eq_iff) simp_all
 
 lemma inj_on_image_Int: "inj_on f C \<Longrightarrow> A \<subseteq> C \<Longrightarrow> B \<subseteq> C \<Longrightarrow> f ` (A \<inter> B) = f ` A \<inter> f ` B"
   unfolding inj_on_def by blast
 
 lemma inj_on_image_set_diff: "inj_on f C \<Longrightarrow> A - B \<subseteq> C \<Longrightarrow> B \<subseteq> C \<Longrightarrow> f ` (A - B) = f ` A - f ` B"
   unfolding inj_on_def by blast
 
 lemma image_Int: "inj f \<Longrightarrow> f ` (A \<inter> B) = f ` A \<inter> f ` B"
   unfolding inj_def by blast
 
 lemma image_set_diff: "inj f \<Longrightarrow> f ` (A - B) = f ` A - f ` B"
   unfolding inj_def by blast
 
 lemma inj_on_image_mem_iff: "inj_on f B \<Longrightarrow> a \<in> B \<Longrightarrow> A \<subseteq> B \<Longrightarrow> f a \<in> f ` A \<longleftrightarrow> a \<in> A"
   by (auto simp: inj_on_def)
 
 lemma inj_image_mem_iff: "inj f \<Longrightarrow> f a \<in> f ` A \<longleftrightarrow> a \<in> A"
   by (blast dest: injD)
 
 lemma inj_image_subset_iff: "inj f \<Longrightarrow> f ` A \<subseteq> f ` B \<longleftrightarrow> A \<subseteq> B"
   by (blast dest: injD)
 
 lemma inj_image_eq_iff: "inj f \<Longrightarrow> f ` A = f ` B \<longleftrightarrow> A = B"
   by (blast dest: injD)
 
 lemma surj_Compl_image_subset: "surj f \<Longrightarrow> - (f ` A) \<subseteq> f ` (- A)"
   by auto
 
 lemma inj_image_Compl_subset: "inj f \<Longrightarrow> f ` (- A) \<subseteq> - (f ` A)"
   by (auto simp: inj_def)
 
 lemma bij_image_Compl_eq: "bij f \<Longrightarrow> f ` (- A) = - (f ` A)"
   by (simp add: bij_def inj_image_Compl_subset surj_Compl_image_subset equalityI)
 
 lemma inj_vimage_singleton: "inj f \<Longrightarrow> f -` {a} \<subseteq> {THE x. f x = a}"
   \<comment> \<open>The inverse image of a singleton under an injective function is included in a singleton.\<close>
   by (simp add: inj_def) (blast intro: the_equality [symmetric])
 
 lemma inj_on_vimage_singleton: "inj_on f A \<Longrightarrow> f -` {a} \<inter> A \<subseteq> {THE x. x \<in> A \<and> f x = a}"
   by (auto simp add: inj_on_def intro: the_equality [symmetric])
 
 lemma (in ordered_ab_group_add) inj_uminus[simp, intro]: "inj_on uminus A"
   by (auto intro!: inj_onI)
 
 lemma (in linorder) strict_mono_imp_inj_on: "strict_mono f \<Longrightarrow> inj_on f A"
   by (auto intro!: inj_onI dest: strict_mono_eq)
 
 lemma bij_betw_byWitness:
   assumes left: "\<forall>a \<in> A. f' (f a) = a"
     and right: "\<forall>a' \<in> A'. f (f' a') = a'"
     and "f ` A \<subseteq> A'"
     and img2: "f' ` A' \<subseteq> A"
   shows "bij_betw f A A'"
   using assms
   unfolding bij_betw_def inj_on_def
 proof safe
   fix a b
   assume "a \<in> A" "b \<in> A"
   with left have "a = f' (f a) \<and> b = f' (f b)" by simp
   moreover assume "f a = f b"
   ultimately show "a = b" by simp
 next
   fix a' assume *: "a' \<in> A'"
   with img2 have "f' a' \<in> A" by blast
   moreover from * right have "a' = f (f' a')" by simp
   ultimately show "a' \<in> f ` A" by blast
 qed
 
 corollary notIn_Un_bij_betw:
   assumes "b \<notin> A"
     and "f b \<notin> A'"
     and "bij_betw f A A'"
   shows "bij_betw f (A \<union> {b}) (A' \<union> {f b})"
 proof -
   have "bij_betw f {b} {f b}"
     unfolding bij_betw_def inj_on_def by simp
   with assms show ?thesis
     using bij_betw_combine[of f A A' "{b}" "{f b}"] by blast
 qed
 
 lemma notIn_Un_bij_betw3:
   assumes "b \<notin> A"
     and "f b \<notin> A'"
   shows "bij_betw f A A' = bij_betw f (A \<union> {b}) (A' \<union> {f b})"
 proof
   assume "bij_betw f A A'"
   then show "bij_betw f (A \<union> {b}) (A' \<union> {f b})"
     using assms notIn_Un_bij_betw [of b A f A'] by blast
 next
   assume *: "bij_betw f (A \<union> {b}) (A' \<union> {f b})"
   have "f ` A = A'"
   proof auto
     fix a
     assume **: "a \<in> A"
     then have "f a \<in> A' \<union> {f b}"
       using * unfolding bij_betw_def by blast
     moreover
     have False if "f a = f b"
     proof -
       have "a = b"
         using * ** that unfolding bij_betw_def inj_on_def by blast
       with \<open>b \<notin> A\<close> ** show ?thesis by blast
     qed
     ultimately show "f a \<in> A'" by blast
   next
     fix a'
     assume **: "a' \<in> A'"
     then have "a' \<in> f ` (A \<union> {b})"
       using * by (auto simp add: bij_betw_def)
     then obtain a where 1: "a \<in> A \<union> {b} \<and> f a = a'" by blast
     moreover
     have False if "a = b" using 1 ** \<open>f b \<notin> A'\<close> that by blast
     ultimately have "a \<in> A" by blast
     with 1 show "a' \<in> f ` A" by blast
   qed
   then show "bij_betw f A A'"
     using * bij_betw_subset[of f "A \<union> {b}" _ A] by blast
 qed
 
 lemma inj_on_disjoint_Un:
   assumes "inj_on f A" and "inj_on g B" 
   and "f ` A \<inter> g ` B = {}"
   shows "inj_on (\<lambda>x. if x \<in> A then f x else g x) (A \<union> B)"
   using assms by (simp add: inj_on_def disjoint_iff) (blast)
 
 lemma bij_betw_disjoint_Un:
   assumes "bij_betw f A C" and "bij_betw g B D" 
   and "A \<inter> B = {}"
   and "C \<inter> D = {}"
   shows "bij_betw (\<lambda>x. if x \<in> A then f x else g x) (A \<union> B) (C \<union> D)"
   using assms by (auto simp: inj_on_disjoint_Un bij_betw_def)
 
 subsubsection \<open>Important examples\<close>
 
 context cancel_semigroup_add
 begin
 
 lemma inj_on_add [simp]:
   "inj_on ((+) a) A"
   by (rule inj_onI) simp
 
 lemma inj_add_left:
   \<open>inj ((+) a)\<close>
   by simp
 
 lemma inj_on_add' [simp]:
   "inj_on (\<lambda>b. b + a) A"
   by (rule inj_onI) simp
 
 lemma bij_betw_add [simp]:
   "bij_betw ((+) a) A B \<longleftrightarrow> (+) a ` A = B"
   by (simp add: bij_betw_def)
 
 end
 
 context ab_group_add
 begin
 
 lemma surj_plus [simp]:
   "surj ((+) a)"
   by (auto intro!: range_eqI [of b "(+) a" "b - a" for b]) (simp add: algebra_simps)
 
 lemma inj_diff_right [simp]:
   \<open>inj (\<lambda>b. b - a)\<close>
 proof -
   have \<open>inj ((+) (- a))\<close>
     by (fact inj_add_left)
   also have \<open>(+) (- a) = (\<lambda>b. b - a)\<close>
     by (simp add: fun_eq_iff)
   finally show ?thesis .
 qed
 
 lemma surj_diff_right [simp]:
   "surj (\<lambda>x. x - a)"
   using surj_plus [of "- a"] by (simp cong: image_cong_simp)
 
 lemma translation_Compl:
   "(+) a ` (- t) = - ((+) a ` t)"
 proof (rule set_eqI)
   fix b
   show "b \<in> (+) a ` (- t) \<longleftrightarrow> b \<in> - (+) a ` t"
     by (auto simp: image_iff algebra_simps intro!: bexI [of _ "b - a"])
 qed
 
 lemma translation_subtract_Compl:
   "(\<lambda>x. x - a) ` (- t) = - ((\<lambda>x. x - a) ` t)"
   using translation_Compl [of "- a" t] by (simp cong: image_cong_simp)
 
 lemma translation_diff:
   "(+) a ` (s - t) = ((+) a ` s) - ((+) a ` t)"
   by auto
 
 lemma translation_subtract_diff:
   "(\<lambda>x. x - a) ` (s - t) = ((\<lambda>x. x - a) ` s) - ((\<lambda>x. x - a) ` t)"
   using translation_diff [of "- a"] by (simp cong: image_cong_simp)
 
 lemma translation_Int:
   "(+) a ` (s \<inter> t) = ((+) a ` s) \<inter> ((+) a ` t)"
   by auto
 
 lemma translation_subtract_Int:
   "(\<lambda>x. x - a) ` (s \<inter> t) = ((\<lambda>x. x - a) ` s) \<inter> ((\<lambda>x. x - a) ` t)"
   using translation_Int [of " -a"] by (simp cong: image_cong_simp)
 
 end
 
 
 subsection \<open>Function Updating\<close>
 
 definition fun_upd :: "('a \<Rightarrow> 'b) \<Rightarrow> 'a \<Rightarrow> 'b \<Rightarrow> ('a \<Rightarrow> 'b)"
   where "fun_upd f a b = (\<lambda>x. if x = a then b else f x)"
 
 nonterminal updbinds and updbind
 
 syntax
   "_updbind" :: "'a \<Rightarrow> 'a \<Rightarrow> updbind"             ("(2_ :=/ _)")
   ""         :: "updbind \<Rightarrow> updbinds"             ("_")
   "_updbinds":: "updbind \<Rightarrow> updbinds \<Rightarrow> updbinds" ("_,/ _")
   "_Update"  :: "'a \<Rightarrow> updbinds \<Rightarrow> 'a"            ("_/'((_)')" [1000, 0] 900)
 
 translations
   "_Update f (_updbinds b bs)" \<rightleftharpoons> "_Update (_Update f b) bs"
   "f(x:=y)" \<rightleftharpoons> "CONST fun_upd f x y"
 
 (* Hint: to define the sum of two functions (or maps), use case_sum.
          A nice infix syntax could be defined by
 notation
   case_sum  (infixr "'(+')"80)
 *)
 
 lemma fun_upd_idem_iff: "f(x:=y) = f \<longleftrightarrow> f x = y"
   unfolding fun_upd_def
   apply safe
    apply (erule subst)
    apply (rule_tac [2] ext)
    apply auto
   done
 
 lemma fun_upd_idem: "f x = y \<Longrightarrow> f(x := y) = f"
   by (simp only: fun_upd_idem_iff)
 
 lemma fun_upd_triv [iff]: "f(x := f x) = f"
   by (simp only: fun_upd_idem)
 
 lemma fun_upd_apply [simp]: "(f(x := y)) z = (if z = x then y else f z)"
   by (simp add: fun_upd_def)
 
 (* fun_upd_apply supersedes these two, but they are useful
    if fun_upd_apply is intentionally removed from the simpset *)
 lemma fun_upd_same: "(f(x := y)) x = y"
   by simp
 
 lemma fun_upd_other: "z \<noteq> x \<Longrightarrow> (f(x := y)) z = f z"
   by simp
 
 lemma fun_upd_upd [simp]: "f(x := y, x := z) = f(x := z)"
   by (simp add: fun_eq_iff)
 
 lemma fun_upd_twist: "a \<noteq> c \<Longrightarrow> (m(a := b))(c := d) = (m(c := d))(a := b)"
   by auto
 
 lemma inj_on_fun_updI: "inj_on f A \<Longrightarrow> y \<notin> f ` A \<Longrightarrow> inj_on (f(x := y)) A"
   by (auto simp: inj_on_def)
 
 lemma fun_upd_image: "f(x := y) ` A = (if x \<in> A then insert y (f ` (A - {x})) else f ` A)"
   by auto
 
 lemma fun_upd_comp: "f \<circ> (g(x := y)) = (f \<circ> g)(x := f y)"
   by auto
 
 lemma fun_upd_eqD: "f(x := y) = g(x := z) \<Longrightarrow> y = z"
   by (simp add: fun_eq_iff split: if_split_asm)
 
 
 subsection \<open>\<open>override_on\<close>\<close>
 
 definition override_on :: "('a \<Rightarrow> 'b) \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'a set \<Rightarrow> 'a \<Rightarrow> 'b"
   where "override_on f g A = (\<lambda>a. if a \<in> A then g a else f a)"
 
 lemma override_on_emptyset[simp]: "override_on f g {} = f"
   by (simp add: override_on_def)
 
 lemma override_on_apply_notin[simp]: "a \<notin> A \<Longrightarrow> (override_on f g A) a = f a"
   by (simp add: override_on_def)
 
 lemma override_on_apply_in[simp]: "a \<in> A \<Longrightarrow> (override_on f g A) a = g a"
   by (simp add: override_on_def)
 
 lemma override_on_insert: "override_on f g (insert x X) = (override_on f g X)(x:=g x)"
   by (simp add: override_on_def fun_eq_iff)
 
 lemma override_on_insert': "override_on f g (insert x X) = (override_on (f(x:=g x)) g X)"
   by (simp add: override_on_def fun_eq_iff)
 
 
 subsection \<open>\<open>swap\<close>\<close>
 
 definition swap :: "'a \<Rightarrow> 'a \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> ('a \<Rightarrow> 'b)"
   where "swap a b f = f (a := f b, b:= f a)"
 
 lemma swap_apply [simp]:
   "swap a b f a = f b"
   "swap a b f b = f a"
   "c \<noteq> a \<Longrightarrow> c \<noteq> b \<Longrightarrow> swap a b f c = f c"
   by (simp_all add: swap_def)
 
 lemma swap_self [simp]: "swap a a f = f"
   by (simp add: swap_def)
 
 lemma swap_commute: "swap a b f = swap b a f"
   by (simp add: fun_upd_def swap_def fun_eq_iff)
 
 lemma swap_nilpotent [simp]: "swap a b (swap a b f) = f"
   by (rule ext) (simp add: fun_upd_def swap_def)
 
 lemma swap_comp_involutory [simp]: "swap a b \<circ> swap a b = id"
   by (rule ext) simp
 
 lemma swap_triple:
   assumes "a \<noteq> c" and "b \<noteq> c"
   shows "swap a b (swap b c (swap a b f)) = swap a c f"
   using assms by (simp add: fun_eq_iff swap_def)
 
 lemma comp_swap: "f \<circ> swap a b g = swap a b (f \<circ> g)"
   by (rule ext) (simp add: fun_upd_def swap_def)
 
 lemma swap_image_eq [simp]:
   assumes "a \<in> A" "b \<in> A"
   shows "swap a b f ` A = f ` A"
 proof -
   have subset: "\<And>f. swap a b f ` A \<subseteq> f ` A"
     using assms by (auto simp: image_iff swap_def)
   then have "swap a b (swap a b f) ` A \<subseteq> (swap a b f) ` A" .
   with subset[of f] show ?thesis by auto
 qed
 
 lemma inj_on_imp_inj_on_swap: "inj_on f A \<Longrightarrow> a \<in> A \<Longrightarrow> b \<in> A \<Longrightarrow> inj_on (swap a b f) A"
   by (auto simp add: inj_on_def swap_def)
 
 lemma inj_on_swap_iff [simp]:
   assumes A: "a \<in> A" "b \<in> A"
   shows "inj_on (swap a b f) A \<longleftrightarrow> inj_on f A"
 proof
   assume "inj_on (swap a b f) A"
   with A have "inj_on (swap a b (swap a b f)) A"
     by (iprover intro: inj_on_imp_inj_on_swap)
   then show "inj_on f A" by simp
 next
   assume "inj_on f A"
   with A show "inj_on (swap a b f) A"
     by (iprover intro: inj_on_imp_inj_on_swap)
 qed
 
 lemma surj_imp_surj_swap: "surj f \<Longrightarrow> surj (swap a b f)"
   by simp
 
 lemma surj_swap_iff [simp]: "surj (swap a b f) \<longleftrightarrow> surj f"
   by simp
 
 lemma bij_betw_swap_iff [simp]: "x \<in> A \<Longrightarrow> y \<in> A \<Longrightarrow> bij_betw (swap x y f) A B \<longleftrightarrow> bij_betw f A B"
   by (auto simp: bij_betw_def)
 
 lemma bij_swap_iff [simp]: "bij (swap a b f) \<longleftrightarrow> bij f"
   by simp
 
 hide_const (open) swap
 
 
 subsection \<open>Inversion of injective functions\<close>
 
 definition the_inv_into :: "'a set \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> ('b \<Rightarrow> 'a)"
   where "the_inv_into A f = (\<lambda>x. THE y. y \<in> A \<and> f y = x)"
 
 lemma the_inv_into_f_f: "inj_on f A \<Longrightarrow> x \<in> A \<Longrightarrow> the_inv_into A f (f x) = x"
   unfolding the_inv_into_def inj_on_def by blast
 
 lemma f_the_inv_into_f: "inj_on f A \<Longrightarrow> y \<in> f ` A  \<Longrightarrow> f (the_inv_into A f y) = y"
   unfolding the_inv_into_def
   by (rule the1I2; blast dest: inj_onD)
 
 lemma f_the_inv_into_f_bij_betw:
   "bij_betw f A B \<Longrightarrow> (bij_betw f A B \<Longrightarrow> x \<in> B) \<Longrightarrow> f (the_inv_into A f x) = x"
   unfolding bij_betw_def by (blast intro: f_the_inv_into_f)
 
 lemma the_inv_into_into: "inj_on f A \<Longrightarrow> x \<in> f ` A \<Longrightarrow> A \<subseteq> B \<Longrightarrow> the_inv_into A f x \<in> B"
   unfolding the_inv_into_def
   by (rule the1I2; blast dest: inj_onD)
 
 lemma the_inv_into_onto [simp]: "inj_on f A \<Longrightarrow> the_inv_into A f ` (f ` A) = A"
   by (fast intro: the_inv_into_into the_inv_into_f_f [symmetric])
 
 lemma the_inv_into_f_eq: "inj_on f A \<Longrightarrow> f x = y \<Longrightarrow> x \<in> A \<Longrightarrow> the_inv_into A f y = x"
   by (force simp add: the_inv_into_f_f)
 
 lemma the_inv_into_comp:
   "inj_on f (g ` A) \<Longrightarrow> inj_on g A \<Longrightarrow> x \<in> f ` g ` A \<Longrightarrow>
     the_inv_into A (f \<circ> g) x = (the_inv_into A g \<circ> the_inv_into (g ` A) f) x"
   apply (rule the_inv_into_f_eq)
     apply (fast intro: comp_inj_on)
    apply (simp add: f_the_inv_into_f the_inv_into_into)
   apply (simp add: the_inv_into_into)
   done
 
 lemma inj_on_the_inv_into: "inj_on f A \<Longrightarrow> inj_on (the_inv_into A f) (f ` A)"
   by (auto intro: inj_onI simp: the_inv_into_f_f)
 
 lemma bij_betw_the_inv_into: "bij_betw f A B \<Longrightarrow> bij_betw (the_inv_into A f) B A"
   by (auto simp add: bij_betw_def inj_on_the_inv_into the_inv_into_into)
 
 lemma bij_betw_iff_bijections:
   "bij_betw f A B \<longleftrightarrow> (\<exists>g. (\<forall>x \<in> A. f x \<in> B \<and> g(f x) = x) \<and> (\<forall>y \<in> B. g y \<in> A \<and> f(g y) = y))"
   (is "?lhs = ?rhs")
 proof
   assume L: ?lhs
   then show ?rhs
     apply (rule_tac x="the_inv_into A f" in exI)
     apply (auto simp: bij_betw_def f_the_inv_into_f the_inv_into_f_f the_inv_into_into)
     done
 qed (force intro: bij_betw_byWitness)
 
 abbreviation the_inv :: "('a \<Rightarrow> 'b) \<Rightarrow> ('b \<Rightarrow> 'a)"
   where "the_inv f \<equiv> the_inv_into UNIV f"
 
 lemma the_inv_f_f: "the_inv f (f x) = x" if "inj f"
   using that UNIV_I by (rule the_inv_into_f_f)
 
 
 subsection \<open>Cantor's Paradox\<close>
 
 theorem Cantors_paradox: "\<nexists>f. f ` A = Pow A"
 proof
   assume "\<exists>f. f ` A = Pow A"
   then obtain f where f: "f ` A = Pow A" ..
   let ?X = "{a \<in> A. a \<notin> f a}"
   have "?X \<in> Pow A" by blast
   then have "?X \<in> f ` A" by (simp only: f)
   then obtain x where "x \<in> A" and "f x = ?X" by blast
   then show False by blast
 qed
 
 subsection \<open>Monotonic functions over a set\<close>
 
 definition "mono_on f A \<equiv> \<forall>r s. r \<in> A \<and> s \<in> A \<and> r \<le> s \<longrightarrow> f r \<le> f s"
 
 lemma mono_onI:
   "(\<And>r s. r \<in> A \<Longrightarrow> s \<in> A \<Longrightarrow> r \<le> s \<Longrightarrow> f r \<le> f s) \<Longrightarrow> mono_on f A"
   unfolding mono_on_def by simp
 
 lemma mono_onD:
   "\<lbrakk>mono_on f A; r \<in> A; s \<in> A; r \<le> s\<rbrakk> \<Longrightarrow> f r \<le> f s"
   unfolding mono_on_def by simp
 
 lemma mono_imp_mono_on: "mono f \<Longrightarrow> mono_on f A"
   unfolding mono_def mono_on_def by auto
 
 lemma mono_on_subset: "mono_on f A \<Longrightarrow> B \<subseteq> A \<Longrightarrow> mono_on f B"
   unfolding mono_on_def by auto
 
 definition "strict_mono_on f A \<equiv> \<forall>r s. r \<in> A \<and> s \<in> A \<and> r < s \<longrightarrow> f r < f s"
 
 lemma strict_mono_onI:
   "(\<And>r s. r \<in> A \<Longrightarrow> s \<in> A \<Longrightarrow> r < s \<Longrightarrow> f r < f s) \<Longrightarrow> strict_mono_on f A"
   unfolding strict_mono_on_def by simp
 
 lemma strict_mono_onD:
   "\<lbrakk>strict_mono_on f A; r \<in> A; s \<in> A; r < s\<rbrakk> \<Longrightarrow> f r < f s"
   unfolding strict_mono_on_def by simp
 
 lemma mono_on_greaterD:
   assumes "mono_on g A" "x \<in> A" "y \<in> A" "g x > (g (y::_::linorder) :: _ :: linorder)"
   shows "x > y"
 proof (rule ccontr)
   assume "\<not>x > y"
   hence "x \<le> y" by (simp add: not_less)
   from assms(1-3) and this have "g x \<le> g y" by (rule mono_onD)
   with assms(4) show False by simp
 qed
 
 lemma strict_mono_inv:
   fixes f :: "('a::linorder) \<Rightarrow> ('b::linorder)"
   assumes "strict_mono f" and "surj f" and inv: "\<And>x. g (f x) = x"
   shows "strict_mono g"
 proof
   fix x y :: 'b assume "x < y"
   from \<open>surj f\<close> obtain x' y' where [simp]: "x = f x'" "y = f y'" by blast
   with \<open>x < y\<close> and \<open>strict_mono f\<close> have "x' < y'" by (simp add: strict_mono_less)
   with inv show "g x < g y" by simp
 qed
 
 lemma strict_mono_on_imp_inj_on:
   assumes "strict_mono_on (f :: (_ :: linorder) \<Rightarrow> (_ :: preorder)) A"
   shows "inj_on f A"
 proof (rule inj_onI)
   fix x y assume "x \<in> A" "y \<in> A" "f x = f y"
   thus "x = y"
     by (cases x y rule: linorder_cases)
        (auto dest: strict_mono_onD[OF assms, of x y] strict_mono_onD[OF assms, of y x])
 qed
 
 lemma strict_mono_on_leD:
   assumes "strict_mono_on (f :: (_ :: linorder) \<Rightarrow> _ :: preorder) A" "x \<in> A" "y \<in> A" "x \<le> y"
   shows "f x \<le> f y"
 proof (insert le_less_linear[of y x], elim disjE)
   assume "x < y"
   with assms have "f x < f y" by (rule_tac strict_mono_onD[OF assms(1)]) simp_all
   thus ?thesis by (rule less_imp_le)
 qed (insert assms, simp)
 
 lemma strict_mono_on_eqD:
   fixes f :: "(_ :: linorder) \<Rightarrow> (_ :: preorder)"
   assumes "strict_mono_on f A" "f x = f y" "x \<in> A" "y \<in> A"
   shows "y = x"
   using assms by (rule_tac linorder_cases[of x y]) (auto dest: strict_mono_onD)
 
 lemma strict_mono_on_imp_mono_on:
   "strict_mono_on (f :: (_ :: linorder) \<Rightarrow> _ :: preorder) A \<Longrightarrow> mono_on f A"
   by (rule mono_onI, rule strict_mono_on_leD)
 
 
 subsection \<open>Setup\<close>
 
 subsubsection \<open>Proof tools\<close>
 
 text \<open>Simplify terms of the form \<open>f(\<dots>,x:=y,\<dots>,x:=z,\<dots>)\<close> to \<open>f(\<dots>,x:=z,\<dots>)\<close>\<close>
 
 simproc_setup fun_upd2 ("f(v := w, x := y)") = \<open>fn _ =>
   let
     fun gen_fun_upd NONE T _ _ = NONE
       | gen_fun_upd (SOME f) T x y = SOME (Const (\<^const_name>\<open>fun_upd\<close>, T) $ f $ x $ y)
     fun dest_fun_T1 (Type (_, T :: Ts)) = T
     fun find_double (t as Const (\<^const_name>\<open>fun_upd\<close>,T) $ f $ x $ y) =
       let
         fun find (Const (\<^const_name>\<open>fun_upd\<close>,T) $ g $ v $ w) =
               if v aconv x then SOME g else gen_fun_upd (find g) T v w
           | find t = NONE
       in (dest_fun_T1 T, gen_fun_upd (find f) T x y) end
 
     val ss = simpset_of \<^context>
 
     fun proc ctxt ct =
       let
         val t = Thm.term_of ct
       in
         (case find_double t of
           (T, NONE) => NONE
         | (T, SOME rhs) =>
             SOME (Goal.prove ctxt [] [] (Logic.mk_equals (t, rhs))
               (fn _ =>
                 resolve_tac ctxt [eq_reflection] 1 THEN
                 resolve_tac ctxt @{thms ext} 1 THEN
                 simp_tac (put_simpset ss ctxt) 1)))
       end
   in proc end
 \<close>
 
 
 subsubsection \<open>Functorial structure of types\<close>
 
 ML_file \<open>Tools/functor.ML\<close>
 
 functor map_fun: map_fun
   by (simp_all add: fun_eq_iff)
 
 functor vimage
   by (simp_all add: fun_eq_iff vimage_comp)
 
 
 text \<open>Legacy theorem names\<close>
 
 lemmas o_def = comp_def
 lemmas o_apply = comp_apply
 lemmas o_assoc = comp_assoc [symmetric]
 lemmas id_o = id_comp
 lemmas o_id = comp_id
 lemmas o_eq_dest = comp_eq_dest
 lemmas o_eq_elim = comp_eq_elim
 lemmas o_eq_dest_lhs = comp_eq_dest_lhs
 lemmas o_eq_id_dest = comp_eq_id_dest
 
 end
diff --git a/src/HOL/Lattices_Big.thy b/src/HOL/Lattices_Big.thy
--- a/src/HOL/Lattices_Big.thy
+++ b/src/HOL/Lattices_Big.thy
@@ -1,1067 +1,1071 @@
 (*  Title:      HOL/Lattices_Big.thy
     Author:     Tobias Nipkow, Lawrence C Paulson and Markus Wenzel
                 with contributions by Jeremy Avigad
 *)
 
 section \<open>Big infimum (minimum) and supremum (maximum) over finite (non-empty) sets\<close>
 
 theory Lattices_Big
   imports Option
 begin
 
 subsection \<open>Generic lattice operations over a set\<close>
 
 subsubsection \<open>Without neutral element\<close>
 
 locale semilattice_set = semilattice
 begin
 
 interpretation comp_fun_idem f
   by standard (simp_all add: fun_eq_iff left_commute)
 
 definition F :: "'a set \<Rightarrow> 'a"
 where
   eq_fold': "F A = the (Finite_Set.fold (\<lambda>x y. Some (case y of None \<Rightarrow> x | Some z \<Rightarrow> f x z)) None A)"
 
 lemma eq_fold:
   assumes "finite A"
   shows "F (insert x A) = Finite_Set.fold f x A"
 proof (rule sym)
   let ?f = "\<lambda>x y. Some (case y of None \<Rightarrow> x | Some z \<Rightarrow> f x z)"
   interpret comp_fun_idem "?f"
     by standard (simp_all add: fun_eq_iff commute left_commute split: option.split)
   from assms show "Finite_Set.fold f x A = F (insert x A)"
   proof induct
     case empty then show ?case by (simp add: eq_fold')
   next
     case (insert y B) then show ?case by (simp add: insert_commute [of x] eq_fold')
   qed
 qed
 
 lemma singleton [simp]:
   "F {x} = x"
   by (simp add: eq_fold)
 
 lemma insert_not_elem:
   assumes "finite A" and "x \<notin> A" and "A \<noteq> {}"
   shows "F (insert x A) = x \<^bold>* F A"
 proof -
   from \<open>A \<noteq> {}\<close> obtain b where "b \<in> A" by blast
   then obtain B where *: "A = insert b B" "b \<notin> B" by (blast dest: mk_disjoint_insert)
   with \<open>finite A\<close> and \<open>x \<notin> A\<close>
     have "finite (insert x B)" and "b \<notin> insert x B" by auto
   then have "F (insert b (insert x B)) = x \<^bold>* F (insert b B)"
     by (simp add: eq_fold)
   then show ?thesis by (simp add: * insert_commute)
 qed
 
 lemma in_idem:
   assumes "finite A" and "x \<in> A"
   shows "x \<^bold>* F A = F A"
 proof -
   from assms have "A \<noteq> {}" by auto
   with \<open>finite A\<close> show ?thesis using \<open>x \<in> A\<close>
     by (induct A rule: finite_ne_induct) (auto simp add: ac_simps insert_not_elem)
 qed
 
 lemma insert [simp]:
   assumes "finite A" and "A \<noteq> {}"
   shows "F (insert x A) = x \<^bold>* F A"
   using assms by (cases "x \<in> A") (simp_all add: insert_absorb in_idem insert_not_elem)
 
 lemma union:
   assumes "finite A" "A \<noteq> {}" and "finite B" "B \<noteq> {}"
   shows "F (A \<union> B) = F A \<^bold>* F B"
   using assms by (induct A rule: finite_ne_induct) (simp_all add: ac_simps)
 
 lemma remove:
   assumes "finite A" and "x \<in> A"
   shows "F A = (if A - {x} = {} then x else x \<^bold>* F (A - {x}))"
 proof -
   from assms obtain B where "A = insert x B" and "x \<notin> B" by (blast dest: mk_disjoint_insert)
   with assms show ?thesis by simp
 qed
 
 lemma insert_remove:
   assumes "finite A"
   shows "F (insert x A) = (if A - {x} = {} then x else x \<^bold>* F (A - {x}))"
   using assms by (cases "x \<in> A") (simp_all add: insert_absorb remove)
 
 lemma subset:
   assumes "finite A" "B \<noteq> {}" and "B \<subseteq> A"
   shows "F B \<^bold>* F A = F A"
 proof -
   from assms have "A \<noteq> {}" and "finite B" by (auto dest: finite_subset)
   with assms show ?thesis by (simp add: union [symmetric] Un_absorb1)
 qed
 
 lemma closed:
   assumes "finite A" "A \<noteq> {}" and elem: "\<And>x y. x \<^bold>* y \<in> {x, y}"
   shows "F A \<in> A"
 using \<open>finite A\<close> \<open>A \<noteq> {}\<close> proof (induct rule: finite_ne_induct)
   case singleton then show ?case by simp
 next
   case insert with elem show ?case by force
 qed
 
 lemma hom_commute:
   assumes hom: "\<And>x y. h (x \<^bold>* y) = h x \<^bold>* h y"
   and N: "finite N" "N \<noteq> {}"
   shows "h (F N) = F (h ` N)"
 using N proof (induct rule: finite_ne_induct)
   case singleton thus ?case by simp
 next
   case (insert n N)
   then have "h (F (insert n N)) = h (n \<^bold>* F N)" by simp
   also have "\<dots> = h n \<^bold>* h (F N)" by (rule hom)
   also have "h (F N) = F (h ` N)" by (rule insert)
   also have "h n \<^bold>* \<dots> = F (insert (h n) (h ` N))"
     using insert by simp
   also have "insert (h n) (h ` N) = h ` insert n N" by simp
   finally show ?case .
 qed
 
 lemma infinite: "\<not> finite A \<Longrightarrow> F A = the None"
   unfolding eq_fold' by (cases "finite (UNIV::'a set)") (auto intro: finite_subset fold_infinite)
 
 end
 
 locale semilattice_order_set = binary?: semilattice_order + semilattice_set
 begin
 
 lemma bounded_iff:
   assumes "finite A" and "A \<noteq> {}"
   shows "x \<^bold>\<le> F A \<longleftrightarrow> (\<forall>a\<in>A. x \<^bold>\<le> a)"
   using assms by (induct rule: finite_ne_induct) simp_all
 
 lemma boundedI:
   assumes "finite A"
   assumes "A \<noteq> {}"
   assumes "\<And>a. a \<in> A \<Longrightarrow> x \<^bold>\<le> a"
   shows "x \<^bold>\<le> F A"
   using assms by (simp add: bounded_iff)
 
 lemma boundedE:
   assumes "finite A" and "A \<noteq> {}" and "x \<^bold>\<le> F A"
   obtains "\<And>a. a \<in> A \<Longrightarrow> x \<^bold>\<le> a"
   using assms by (simp add: bounded_iff)
 
 lemma coboundedI:
   assumes "finite A"
     and "a \<in> A"
   shows "F A \<^bold>\<le> a"
 proof -
   from assms have "A \<noteq> {}" by auto
   from \<open>finite A\<close> \<open>A \<noteq> {}\<close> \<open>a \<in> A\<close> show ?thesis
   proof (induct rule: finite_ne_induct)
     case singleton thus ?case by (simp add: refl)
   next
     case (insert x B)
     from insert have "a = x \<or> a \<in> B" by simp
     then show ?case using insert by (auto intro: coboundedI2)
   qed
 qed
 
 lemma subset_imp:
   assumes "A \<subseteq> B" and "A \<noteq> {}" and "finite B"
   shows "F B \<^bold>\<le> F A"
 proof (cases "A = B")
   case True then show ?thesis by (simp add: refl)
 next
   case False
   have B: "B = A \<union> (B - A)" using \<open>A \<subseteq> B\<close> by blast
   then have "F B = F (A \<union> (B - A))" by simp
   also have "\<dots> = F A \<^bold>* F (B - A)" using False assms by (subst union) (auto intro: finite_subset)
   also have "\<dots> \<^bold>\<le> F A" by simp
   finally show ?thesis .
 qed
 
 end
 
 
 subsubsection \<open>With neutral element\<close>
 
 locale semilattice_neutr_set = semilattice_neutr
 begin
 
 interpretation comp_fun_idem f
   by standard (simp_all add: fun_eq_iff left_commute)
 
 definition F :: "'a set \<Rightarrow> 'a"
 where
   eq_fold: "F A = Finite_Set.fold f \<^bold>1 A"
 
 lemma infinite [simp]:
   "\<not> finite A \<Longrightarrow> F A = \<^bold>1"
   by (simp add: eq_fold)
 
 lemma empty [simp]:
   "F {} = \<^bold>1"
   by (simp add: eq_fold)
 
 lemma insert [simp]:
   assumes "finite A"
   shows "F (insert x A) = x \<^bold>* F A"
   using assms by (simp add: eq_fold)
 
 lemma in_idem:
   assumes "finite A" and "x \<in> A"
   shows "x \<^bold>* F A = F A"
 proof -
   from assms have "A \<noteq> {}" by auto
   with \<open>finite A\<close> show ?thesis using \<open>x \<in> A\<close>
     by (induct A rule: finite_ne_induct) (auto simp add: ac_simps)
 qed
 
 lemma union:
   assumes "finite A" and "finite B"
   shows "F (A \<union> B) = F A \<^bold>* F B"
   using assms by (induct A) (simp_all add: ac_simps)
 
 lemma remove:
   assumes "finite A" and "x \<in> A"
   shows "F A = x \<^bold>* F (A - {x})"
 proof -
   from assms obtain B where "A = insert x B" and "x \<notin> B" by (blast dest: mk_disjoint_insert)
   with assms show ?thesis by simp
 qed
 
 lemma insert_remove:
   assumes "finite A"
   shows "F (insert x A) = x \<^bold>* F (A - {x})"
   using assms by (cases "x \<in> A") (simp_all add: insert_absorb remove)
 
 lemma subset:
   assumes "finite A" and "B \<subseteq> A"
   shows "F B \<^bold>* F A = F A"
 proof -
   from assms have "finite B" by (auto dest: finite_subset)
   with assms show ?thesis by (simp add: union [symmetric] Un_absorb1)
 qed
 
 lemma closed:
   assumes "finite A" "A \<noteq> {}" and elem: "\<And>x y. x \<^bold>* y \<in> {x, y}"
   shows "F A \<in> A"
 using \<open>finite A\<close> \<open>A \<noteq> {}\<close> proof (induct rule: finite_ne_induct)
   case singleton then show ?case by simp
 next
   case insert with elem show ?case by force
 qed
 
 end
 
 locale semilattice_order_neutr_set = binary?: semilattice_neutr_order + semilattice_neutr_set
 begin
 
 lemma bounded_iff:
   assumes "finite A"
   shows "x \<^bold>\<le> F A \<longleftrightarrow> (\<forall>a\<in>A. x \<^bold>\<le> a)"
   using assms by (induct A) simp_all
 
 lemma boundedI:
   assumes "finite A"
   assumes "\<And>a. a \<in> A \<Longrightarrow> x \<^bold>\<le> a"
   shows "x \<^bold>\<le> F A"
   using assms by (simp add: bounded_iff)
 
 lemma boundedE:
   assumes "finite A" and "x \<^bold>\<le> F A"
   obtains "\<And>a. a \<in> A \<Longrightarrow> x \<^bold>\<le> a"
   using assms by (simp add: bounded_iff)
 
 lemma coboundedI:
   assumes "finite A"
     and "a \<in> A"
   shows "F A \<^bold>\<le> a"
 proof -
   from assms have "A \<noteq> {}" by auto
   from \<open>finite A\<close> \<open>A \<noteq> {}\<close> \<open>a \<in> A\<close> show ?thesis
   proof (induct rule: finite_ne_induct)
     case singleton thus ?case by (simp add: refl)
   next
     case (insert x B)
     from insert have "a = x \<or> a \<in> B" by simp
     then show ?case using insert by (auto intro: coboundedI2)
   qed
 qed
 
 lemma subset_imp:
   assumes "A \<subseteq> B" and "finite B"
   shows "F B \<^bold>\<le> F A"
 proof (cases "A = B")
   case True then show ?thesis by (simp add: refl)
 next
   case False
   have B: "B = A \<union> (B - A)" using \<open>A \<subseteq> B\<close> by blast
   then have "F B = F (A \<union> (B - A))" by simp
   also have "\<dots> = F A \<^bold>* F (B - A)" using False assms by (subst union) (auto intro: finite_subset)
   also have "\<dots> \<^bold>\<le> F A" by simp
   finally show ?thesis .
 qed
 
 end
 
 
 subsection \<open>Lattice operations on finite sets\<close>
 
 context semilattice_inf
 begin
 
 sublocale Inf_fin: semilattice_order_set inf less_eq less
 defines
   Inf_fin ("\<Sqinter>\<^sub>f\<^sub>i\<^sub>n _" [900] 900) = Inf_fin.F ..
 
 end
 
 context semilattice_sup
 begin
 
 sublocale Sup_fin: semilattice_order_set sup greater_eq greater
 defines
   Sup_fin ("\<Squnion>\<^sub>f\<^sub>i\<^sub>n _" [900] 900) = Sup_fin.F ..
 
 end
 
 
 subsection \<open>Infimum and Supremum over non-empty sets\<close>
 
 context lattice
 begin
 
 lemma Inf_fin_le_Sup_fin [simp]: 
   assumes "finite A" and "A \<noteq> {}"
   shows "\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA \<le> \<Squnion>\<^sub>f\<^sub>i\<^sub>nA"
 proof -
   from \<open>A \<noteq> {}\<close> obtain a where "a \<in> A" by blast
   with \<open>finite A\<close> have "\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA \<le> a" by (rule Inf_fin.coboundedI)
   moreover from \<open>finite A\<close> \<open>a \<in> A\<close> have "a \<le> \<Squnion>\<^sub>f\<^sub>i\<^sub>nA" by (rule Sup_fin.coboundedI)
   ultimately show ?thesis by (rule order_trans)
 qed
 
 lemma sup_Inf_absorb [simp]:
   "finite A \<Longrightarrow> a \<in> A \<Longrightarrow> \<Sqinter>\<^sub>f\<^sub>i\<^sub>nA \<squnion> a = a"
   by (rule sup_absorb2) (rule Inf_fin.coboundedI)
 
 lemma inf_Sup_absorb [simp]:
   "finite A \<Longrightarrow> a \<in> A \<Longrightarrow> a \<sqinter> \<Squnion>\<^sub>f\<^sub>i\<^sub>nA = a"
   by (rule inf_absorb1) (rule Sup_fin.coboundedI)
 
 end
 
 context distrib_lattice
 begin
 
 lemma sup_Inf1_distrib:
   assumes "finite A"
     and "A \<noteq> {}"
   shows "sup x (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA) = \<Sqinter>\<^sub>f\<^sub>i\<^sub>n{sup x a|a. a \<in> A}"
 using assms by (simp add: image_def Inf_fin.hom_commute [where h="sup x", OF sup_inf_distrib1])
   (rule arg_cong [where f="Inf_fin"], blast)
 
 lemma sup_Inf2_distrib:
   assumes A: "finite A" "A \<noteq> {}" and B: "finite B" "B \<noteq> {}"
   shows "sup (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA) (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nB) = \<Sqinter>\<^sub>f\<^sub>i\<^sub>n{sup a b|a b. a \<in> A \<and> b \<in> B}"
 using A proof (induct rule: finite_ne_induct)
   case singleton then show ?case
     by (simp add: sup_Inf1_distrib [OF B])
 next
   case (insert x A)
   have finB: "finite {sup x b |b. b \<in> B}"
     by (rule finite_surj [where f = "sup x", OF B(1)], auto)
   have finAB: "finite {sup a b |a b. a \<in> A \<and> b \<in> B}"
   proof -
     have "{sup a b |a b. a \<in> A \<and> b \<in> B} = (\<Union>a\<in>A. \<Union>b\<in>B. {sup a b})"
       by blast
     thus ?thesis by(simp add: insert(1) B(1))
   qed
   have ne: "{sup a b |a b. a \<in> A \<and> b \<in> B} \<noteq> {}" using insert B by blast
   have "sup (\<Sqinter>\<^sub>f\<^sub>i\<^sub>n(insert x A)) (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nB) = sup (inf x (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA)) (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nB)"
     using insert by simp
   also have "\<dots> = inf (sup x (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nB)) (sup (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA) (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nB))" by(rule sup_inf_distrib2)
   also have "\<dots> = inf (\<Sqinter>\<^sub>f\<^sub>i\<^sub>n{sup x b|b. b \<in> B}) (\<Sqinter>\<^sub>f\<^sub>i\<^sub>n{sup a b|a b. a \<in> A \<and> b \<in> B})"
     using insert by(simp add:sup_Inf1_distrib[OF B])
   also have "\<dots> = \<Sqinter>\<^sub>f\<^sub>i\<^sub>n({sup x b |b. b \<in> B} \<union> {sup a b |a b. a \<in> A \<and> b \<in> B})"
     (is "_ = \<Sqinter>\<^sub>f\<^sub>i\<^sub>n?M")
     using B insert
     by (simp add: Inf_fin.union [OF finB _ finAB ne])
   also have "?M = {sup a b |a b. a \<in> insert x A \<and> b \<in> B}"
     by blast
   finally show ?case .
 qed
 
 lemma inf_Sup1_distrib:
   assumes "finite A" and "A \<noteq> {}"
   shows "inf x (\<Squnion>\<^sub>f\<^sub>i\<^sub>nA) = \<Squnion>\<^sub>f\<^sub>i\<^sub>n{inf x a|a. a \<in> A}"
 using assms by (simp add: image_def Sup_fin.hom_commute [where h="inf x", OF inf_sup_distrib1])
   (rule arg_cong [where f="Sup_fin"], blast)
 
 lemma inf_Sup2_distrib:
   assumes A: "finite A" "A \<noteq> {}" and B: "finite B" "B \<noteq> {}"
   shows "inf (\<Squnion>\<^sub>f\<^sub>i\<^sub>nA) (\<Squnion>\<^sub>f\<^sub>i\<^sub>nB) = \<Squnion>\<^sub>f\<^sub>i\<^sub>n{inf a b|a b. a \<in> A \<and> b \<in> B}"
 using A proof (induct rule: finite_ne_induct)
   case singleton thus ?case
     by(simp add: inf_Sup1_distrib [OF B])
 next
   case (insert x A)
   have finB: "finite {inf x b |b. b \<in> B}"
     by(rule finite_surj[where f = "%b. inf x b", OF B(1)], auto)
   have finAB: "finite {inf a b |a b. a \<in> A \<and> b \<in> B}"
   proof -
     have "{inf a b |a b. a \<in> A \<and> b \<in> B} = (\<Union>a\<in>A. \<Union>b\<in>B. {inf a b})"
       by blast
     thus ?thesis by(simp add: insert(1) B(1))
   qed
   have ne: "{inf a b |a b. a \<in> A \<and> b \<in> B} \<noteq> {}" using insert B by blast
   have "inf (\<Squnion>\<^sub>f\<^sub>i\<^sub>n(insert x A)) (\<Squnion>\<^sub>f\<^sub>i\<^sub>nB) = inf (sup x (\<Squnion>\<^sub>f\<^sub>i\<^sub>nA)) (\<Squnion>\<^sub>f\<^sub>i\<^sub>nB)"
     using insert by simp
   also have "\<dots> = sup (inf x (\<Squnion>\<^sub>f\<^sub>i\<^sub>nB)) (inf (\<Squnion>\<^sub>f\<^sub>i\<^sub>nA) (\<Squnion>\<^sub>f\<^sub>i\<^sub>nB))" by(rule inf_sup_distrib2)
   also have "\<dots> = sup (\<Squnion>\<^sub>f\<^sub>i\<^sub>n{inf x b|b. b \<in> B}) (\<Squnion>\<^sub>f\<^sub>i\<^sub>n{inf a b|a b. a \<in> A \<and> b \<in> B})"
     using insert by(simp add:inf_Sup1_distrib[OF B])
   also have "\<dots> = \<Squnion>\<^sub>f\<^sub>i\<^sub>n({inf x b |b. b \<in> B} \<union> {inf a b |a b. a \<in> A \<and> b \<in> B})"
     (is "_ = \<Squnion>\<^sub>f\<^sub>i\<^sub>n?M")
     using B insert
     by (simp add: Sup_fin.union [OF finB _ finAB ne])
   also have "?M = {inf a b |a b. a \<in> insert x A \<and> b \<in> B}"
     by blast
   finally show ?case .
 qed
 
 end
 
 context complete_lattice
 begin
 
 lemma Inf_fin_Inf:
   assumes "finite A" and "A \<noteq> {}"
   shows "\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA = \<Sqinter>A"
 proof -
   from assms obtain b B where "A = insert b B" and "finite B" by auto
   then show ?thesis
     by (simp add: Inf_fin.eq_fold inf_Inf_fold_inf inf.commute [of b])
 qed
 
 lemma Sup_fin_Sup:
   assumes "finite A" and "A \<noteq> {}"
   shows "\<Squnion>\<^sub>f\<^sub>i\<^sub>nA = \<Squnion>A"
 proof -
   from assms obtain b B where "A = insert b B" and "finite B" by auto
   then show ?thesis
     by (simp add: Sup_fin.eq_fold sup_Sup_fold_sup sup.commute [of b])
 qed
 
 end
 
 
 subsection \<open>Minimum and Maximum over non-empty sets\<close>
 
 context linorder
 begin
 
 sublocale Min: semilattice_order_set min less_eq less
   + Max: semilattice_order_set max greater_eq greater
 defines
   Min = Min.F and Max = Max.F ..
 
 end
 
 syntax
   "_MIN1"     :: "pttrns \<Rightarrow> 'b \<Rightarrow> 'b"           ("(3MIN _./ _)" [0, 10] 10)
   "_MIN"      :: "pttrn \<Rightarrow> 'a set \<Rightarrow> 'b \<Rightarrow> 'b"  ("(3MIN _\<in>_./ _)" [0, 0, 10] 10)
   "_MAX1"     :: "pttrns \<Rightarrow> 'b \<Rightarrow> 'b"           ("(3MAX _./ _)" [0, 10] 10)
   "_MAX"      :: "pttrn \<Rightarrow> 'a set \<Rightarrow> 'b \<Rightarrow> 'b"  ("(3MAX _\<in>_./ _)" [0, 0, 10] 10)
 
 translations
   "MIN x y. f"   \<rightleftharpoons> "MIN x. MIN y. f"
   "MIN x. f"     \<rightleftharpoons> "CONST Min (CONST range (\<lambda>x. f))"
   "MIN x\<in>A. f"   \<rightleftharpoons> "CONST Min ((\<lambda>x. f) ` A)"
   "MAX x y. f"   \<rightleftharpoons> "MAX x. MAX y. f"
   "MAX x. f"     \<rightleftharpoons> "CONST Max (CONST range (\<lambda>x. f))"
   "MAX x\<in>A. f"   \<rightleftharpoons> "CONST Max ((\<lambda>x. f) ` A)"
 
 text \<open>An aside: \<^const>\<open>Min\<close>/\<^const>\<open>Max\<close> on linear orders as special case of \<^const>\<open>Inf_fin\<close>/\<^const>\<open>Sup_fin\<close>\<close>
 
 lemma Inf_fin_Min:
   "Inf_fin = (Min :: 'a::{semilattice_inf, linorder} set \<Rightarrow> 'a)"
   by (simp add: Inf_fin_def Min_def inf_min)
 
 lemma Sup_fin_Max:
   "Sup_fin = (Max :: 'a::{semilattice_sup, linorder} set \<Rightarrow> 'a)"
   by (simp add: Sup_fin_def Max_def sup_max)
 
 context linorder
 begin
 
 lemma dual_min:
   "ord.min greater_eq = max"
   by (auto simp add: ord.min_def max_def fun_eq_iff)
 
 lemma dual_max:
   "ord.max greater_eq = min"
   by (auto simp add: ord.max_def min_def fun_eq_iff)
 
 lemma dual_Min:
   "linorder.Min greater_eq = Max"
 proof -
   interpret dual: linorder greater_eq greater by (fact dual_linorder)
   show ?thesis by (simp add: dual.Min_def dual_min Max_def)
 qed
 
 lemma dual_Max:
   "linorder.Max greater_eq = Min"
 proof -
   interpret dual: linorder greater_eq greater by (fact dual_linorder)
   show ?thesis by (simp add: dual.Max_def dual_max Min_def)
 qed
 
 lemmas Min_singleton = Min.singleton
 lemmas Max_singleton = Max.singleton
 lemmas Min_insert = Min.insert
 lemmas Max_insert = Max.insert
 lemmas Min_Un = Min.union
 lemmas Max_Un = Max.union
 lemmas hom_Min_commute = Min.hom_commute
 lemmas hom_Max_commute = Max.hom_commute
 
 lemma Min_in [simp]:
   assumes "finite A" and "A \<noteq> {}"
   shows "Min A \<in> A"
   using assms by (auto simp add: min_def Min.closed)
 
 lemma Max_in [simp]:
   assumes "finite A" and "A \<noteq> {}"
   shows "Max A \<in> A"
   using assms by (auto simp add: max_def Max.closed)
 
 lemma Min_insert2:
   assumes "finite A" and min: "\<And>b. b \<in> A \<Longrightarrow> a \<le> b"
   shows "Min (insert a A) = a"
 proof (cases "A = {}")
   case True
   then show ?thesis by simp
 next
   case False
   with \<open>finite A\<close> have "Min (insert a A) = min a (Min A)"
     by simp
   moreover from \<open>finite A\<close> \<open>A \<noteq> {}\<close> min have "a \<le> Min A" by simp
   ultimately show ?thesis by (simp add: min.absorb1)
 qed
 
 lemma Max_insert2:
   assumes "finite A" and max: "\<And>b. b \<in> A \<Longrightarrow> b \<le> a"
   shows "Max (insert a A) = a"
 proof (cases "A = {}")
   case True
   then show ?thesis by simp
 next
   case False
   with \<open>finite A\<close> have "Max (insert a A) = max a (Max A)"
     by simp
   moreover from \<open>finite A\<close> \<open>A \<noteq> {}\<close> max have "Max A \<le> a" by simp
   ultimately show ?thesis by (simp add: max.absorb1)
 qed
 
 lemma Max_const[simp]: "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> Max ((\<lambda>_. c) ` A) = c"
 using Max_in image_is_empty by blast
 
 lemma Min_const[simp]: "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> Min ((\<lambda>_. c) ` A) = c"
 using Min_in image_is_empty by blast
 
 lemma Min_le [simp]:
   assumes "finite A" and "x \<in> A"
   shows "Min A \<le> x"
   using assms by (fact Min.coboundedI)
 
 lemma Max_ge [simp]:
   assumes "finite A" and "x \<in> A"
   shows "x \<le> Max A"
   using assms by (fact Max.coboundedI)
 
 lemma Min_eqI:
   assumes "finite A"
   assumes "\<And>y. y \<in> A \<Longrightarrow> y \<ge> x"
     and "x \<in> A"
   shows "Min A = x"
 proof (rule antisym)
   from \<open>x \<in> A\<close> have "A \<noteq> {}" by auto
   with assms show "Min A \<ge> x" by simp
 next
   from assms show "x \<ge> Min A" by simp
 qed
 
 lemma Max_eqI:
   assumes "finite A"
   assumes "\<And>y. y \<in> A \<Longrightarrow> y \<le> x"
     and "x \<in> A"
   shows "Max A = x"
 proof (rule antisym)
   from \<open>x \<in> A\<close> have "A \<noteq> {}" by auto
   with assms show "Max A \<le> x" by simp
 next
   from assms show "x \<le> Max A" by simp
 qed
 
 lemma eq_Min_iff:
   "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> m = Min A  \<longleftrightarrow>  m \<in> A \<and> (\<forall>a \<in> A. m \<le> a)"
 by (meson Min_in Min_le antisym)
 
 lemma Min_eq_iff:
   "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> Min A = m  \<longleftrightarrow>  m \<in> A \<and> (\<forall>a \<in> A. m \<le> a)"
 by (meson Min_in Min_le antisym)
 
 lemma eq_Max_iff:
   "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> m = Max A  \<longleftrightarrow>  m \<in> A \<and> (\<forall>a \<in> A. a \<le> m)"
 by (meson Max_in Max_ge antisym)
 
 lemma Max_eq_iff:
   "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> Max A = m  \<longleftrightarrow>  m \<in> A \<and> (\<forall>a \<in> A. a \<le> m)"
 by (meson Max_in Max_ge antisym)
 
 context
   fixes A :: "'a set"
   assumes fin_nonempty: "finite A" "A \<noteq> {}"
 begin
 
 lemma Min_ge_iff [simp]:
   "x \<le> Min A \<longleftrightarrow> (\<forall>a\<in>A. x \<le> a)"
   using fin_nonempty by (fact Min.bounded_iff)
 
 lemma Max_le_iff [simp]:
   "Max A \<le> x \<longleftrightarrow> (\<forall>a\<in>A. a \<le> x)"
   using fin_nonempty by (fact Max.bounded_iff)
 
 lemma Min_gr_iff [simp]:
   "x < Min A \<longleftrightarrow> (\<forall>a\<in>A. x < a)"
   using fin_nonempty  by (induct rule: finite_ne_induct) simp_all
 
 lemma Max_less_iff [simp]:
   "Max A < x \<longleftrightarrow> (\<forall>a\<in>A. a < x)"
   using fin_nonempty by (induct rule: finite_ne_induct) simp_all
 
 lemma Min_le_iff:
   "Min A \<le> x \<longleftrightarrow> (\<exists>a\<in>A. a \<le> x)"
   using fin_nonempty by (induct rule: finite_ne_induct) (simp_all add: min_le_iff_disj)
 
 lemma Max_ge_iff:
   "x \<le> Max A \<longleftrightarrow> (\<exists>a\<in>A. x \<le> a)"
   using fin_nonempty by (induct rule: finite_ne_induct) (simp_all add: le_max_iff_disj)
 
 lemma Min_less_iff:
   "Min A < x \<longleftrightarrow> (\<exists>a\<in>A. a < x)"
   using fin_nonempty by (induct rule: finite_ne_induct) (simp_all add: min_less_iff_disj)
 
 lemma Max_gr_iff:
   "x < Max A \<longleftrightarrow> (\<exists>a\<in>A. x < a)"
   using fin_nonempty by (induct rule: finite_ne_induct) (simp_all add: less_max_iff_disj)
 
 end
 
 lemma Max_eq_if:
   assumes "finite A"  "finite B"  "\<forall>a\<in>A. \<exists>b\<in>B. a \<le> b"  "\<forall>b\<in>B. \<exists>a\<in>A. b \<le> a"
   shows "Max A = Max B"
 proof cases
   assume "A = {}" thus ?thesis using assms by simp
 next
   assume "A \<noteq> {}" thus ?thesis using assms
     by(blast intro: antisym Max_in Max_ge_iff[THEN iffD2])
 qed
 
 lemma Min_antimono:
   assumes "M \<subseteq> N" and "M \<noteq> {}" and "finite N"
   shows "Min N \<le> Min M"
   using assms by (fact Min.subset_imp)
 
 lemma Max_mono:
   assumes "M \<subseteq> N" and "M \<noteq> {}" and "finite N"
   shows "Max M \<le> Max N"
   using assms by (fact Max.subset_imp)
 
 lemma mono_Min_commute:
   assumes "mono f"
   assumes "finite A" and "A \<noteq> {}"
   shows "f (Min A) = Min (f ` A)"
 proof (rule linorder_class.Min_eqI [symmetric])
   from \<open>finite A\<close> show "finite (f ` A)" by simp
   from assms show "f (Min A) \<in> f ` A" by simp
   fix x
   assume "x \<in> f ` A"
   then obtain y where "y \<in> A" and "x = f y" ..
   with assms have "Min A \<le> y" by auto
   with \<open>mono f\<close> have "f (Min A) \<le> f y" by (rule monoE)
   with \<open>x = f y\<close> show "f (Min A) \<le> x" by simp
 qed
 
 lemma mono_Max_commute:
   assumes "mono f"
   assumes "finite A" and "A \<noteq> {}"
   shows "f (Max A) = Max (f ` A)"
 proof (rule linorder_class.Max_eqI [symmetric])
   from \<open>finite A\<close> show "finite (f ` A)" by simp
   from assms show "f (Max A) \<in> f ` A" by simp
   fix x
   assume "x \<in> f ` A"
   then obtain y where "y \<in> A" and "x = f y" ..
   with assms have "y \<le> Max A" by auto
   with \<open>mono f\<close> have "f y \<le> f (Max A)" by (rule monoE)
   with \<open>x = f y\<close> show "x \<le> f (Max A)" by simp
 qed
 
 lemma finite_linorder_max_induct [consumes 1, case_names empty insert]:
   assumes fin: "finite A"
   and empty: "P {}" 
   and insert: "\<And>b A. finite A \<Longrightarrow> \<forall>a\<in>A. a < b \<Longrightarrow> P A \<Longrightarrow> P (insert b A)"
   shows "P A"
 using fin empty insert
 proof (induct rule: finite_psubset_induct)
   case (psubset A)
   have IH: "\<And>B. \<lbrakk>B < A; P {}; (\<And>A b. \<lbrakk>finite A; \<forall>a\<in>A. a<b; P A\<rbrakk> \<Longrightarrow> P (insert b A))\<rbrakk> \<Longrightarrow> P B" by fact 
   have fin: "finite A" by fact 
   have empty: "P {}" by fact
   have step: "\<And>b A. \<lbrakk>finite A; \<forall>a\<in>A. a < b; P A\<rbrakk> \<Longrightarrow> P (insert b A)" by fact
   show "P A"
   proof (cases "A = {}")
     assume "A = {}" 
     then show "P A" using \<open>P {}\<close> by simp
   next
     let ?B = "A - {Max A}" 
     let ?A = "insert (Max A) ?B"
     have "finite ?B" using \<open>finite A\<close> by simp
     assume "A \<noteq> {}"
     with \<open>finite A\<close> have "Max A \<in> A" by auto
     then have A: "?A = A" using insert_Diff_single insert_absorb by auto
     then have "P ?B" using \<open>P {}\<close> step IH [of ?B] by blast
     moreover 
     have "\<forall>a\<in>?B. a < Max A" using Max_ge [OF \<open>finite A\<close>] by fastforce
     ultimately show "P A" using A insert_Diff_single step [OF \<open>finite ?B\<close>] by fastforce
   qed
 qed
 
 lemma finite_linorder_min_induct [consumes 1, case_names empty insert]:
   "\<lbrakk>finite A; P {}; \<And>b A. \<lbrakk>finite A; \<forall>a\<in>A. b < a; P A\<rbrakk> \<Longrightarrow> P (insert b A)\<rbrakk> \<Longrightarrow> P A"
   by (rule linorder.finite_linorder_max_induct [OF dual_linorder])
 
 lemma finite_ranking_induct[consumes 1, case_names empty insert]:
   fixes f :: "'b \<Rightarrow> 'a"
   assumes "finite S"
   assumes "P {}" 
   assumes "\<And>x S. finite S \<Longrightarrow> (\<And>y. y \<in> S \<Longrightarrow> f y \<le> f x) \<Longrightarrow> P S \<Longrightarrow> P (insert x S)"
   shows "P S"
   using \<open>finite S\<close> 
 proof (induction rule: finite_psubset_induct)
   case (psubset A)
   {
     assume "A \<noteq> {}"
     hence "f ` A \<noteq> {}" and "finite (f ` A)"
       using psubset finite_image_iff by simp+ 
     then obtain a where "f a = Max (f ` A)" and "a \<in> A"
       by (metis Max_in[of "f ` A"] imageE)
     then have "P (A - {a})"
       using psubset member_remove by blast 
     moreover 
     have "\<And>y. y \<in> A \<Longrightarrow> f y \<le> f a"
       using \<open>f a = Max (f ` A)\<close> \<open>finite (f ` A)\<close> by simp
     ultimately
     have ?case
       by (metis \<open>a \<in> A\<close> DiffD1 insert_Diff assms(3) finite_Diff psubset.hyps)
   }
   thus ?case
     using assms(2) by blast
 qed
 
 lemma Least_Min:
   assumes "finite {a. P a}" and "\<exists>a. P a"
   shows "(LEAST a. P a) = Min {a. P a}"
 proof -
   { fix A :: "'a set"
     assume A: "finite A" "A \<noteq> {}"
     have "(LEAST a. a \<in> A) = Min A"
     using A proof (induct A rule: finite_ne_induct)
       case singleton show ?case by (rule Least_equality) simp_all
     next
       case (insert a A)
       have "(LEAST b. b = a \<or> b \<in> A) = min a (LEAST a. a \<in> A)"
         by (auto intro!: Least_equality simp add: min_def not_le Min_le_iff insert.hyps dest!: less_imp_le)
       with insert show ?case by simp
     qed
   } from this [of "{a. P a}"] assms show ?thesis by simp
 qed
 
 lemma infinite_growing:
   assumes "X \<noteq> {}"
   assumes *: "\<And>x. x \<in> X \<Longrightarrow> \<exists>y\<in>X. y > x"
   shows "\<not> finite X"
 proof
   assume "finite X"
   with \<open>X \<noteq> {}\<close> have "Max X \<in> X" "\<forall>x\<in>X. x \<le> Max X"
     by auto
   with *[of "Max X"] show False
     by auto
 qed
 
 end
 
 lemma sum_le_card_Max: "finite A \<Longrightarrow> sum f A \<le> card A * Max (f ` A)"
 using sum_bounded_above[of A f "Max (f ` A)"] by simp
 
 lemma card_Min_le_sum: "finite A \<Longrightarrow> card A * Min (f ` A) \<le> sum f A"
 using sum_bounded_below[of A "Min (f ` A)" f] by simp
 
 context linordered_ab_semigroup_add
 begin
 
 lemma Min_add_commute:
   fixes k
   assumes "finite S" and "S \<noteq> {}"
   shows "Min ((\<lambda>x. f x + k) ` S) = Min(f ` S) + k"
 proof -
   have m: "\<And>x y. min x y + k = min (x+k) (y+k)"
     by(simp add: min_def antisym add_right_mono)
   have "(\<lambda>x. f x + k) ` S = (\<lambda>y. y + k) ` (f ` S)" by auto
   also have "Min \<dots> = Min (f ` S) + k"
     using assms hom_Min_commute [of "\<lambda>y. y+k" "f ` S", OF m, symmetric] by simp
   finally show ?thesis by simp
 qed
 
 lemma Max_add_commute:
   fixes k
   assumes "finite S" and "S \<noteq> {}"
   shows "Max ((\<lambda>x. f x + k) ` S) = Max(f ` S) + k"
 proof -
   have m: "\<And>x y. max x y + k = max (x+k) (y+k)"
     by(simp add: max_def antisym add_right_mono)
   have "(\<lambda>x. f x + k) ` S = (\<lambda>y. y + k) ` (f ` S)" by auto
   also have "Max \<dots> = Max (f ` S) + k"
     using assms hom_Max_commute [of "\<lambda>y. y+k" "f ` S", OF m, symmetric] by simp
   finally show ?thesis by simp
 qed
 
 end
 
 context linordered_ab_group_add
 begin
 
 lemma minus_Max_eq_Min [simp]:
   "finite S \<Longrightarrow> S \<noteq> {} \<Longrightarrow> - Max S = Min (uminus ` S)"
   by (induct S rule: finite_ne_induct) (simp_all add: minus_max_eq_min)
 
 lemma minus_Min_eq_Max [simp]:
   "finite S \<Longrightarrow> S \<noteq> {} \<Longrightarrow> - Min S = Max (uminus ` S)"
   by (induct S rule: finite_ne_induct) (simp_all add: minus_min_eq_max)
 
 end
 
 context complete_linorder
 begin
 
 lemma Min_Inf:
   assumes "finite A" and "A \<noteq> {}"
   shows "Min A = Inf A"
 proof -
   from assms obtain b B where "A = insert b B" and "finite B" by auto
   then show ?thesis
     by (simp add: Min.eq_fold complete_linorder_inf_min [symmetric] inf_Inf_fold_inf inf.commute [of b])
 qed
 
 lemma Max_Sup:
   assumes "finite A" and "A \<noteq> {}"
   shows "Max A = Sup A"
 proof -
   from assms obtain b B where "A = insert b B" and "finite B" by auto
   then show ?thesis
     by (simp add: Max.eq_fold complete_linorder_sup_max [symmetric] sup_Sup_fold_sup sup.commute [of b])
 qed
 
 end
 
+lemma disjnt_ge_max: \<^marker>\<open>contributor \<open>Lars Hupel\<close>\<close>
+  \<open>disjnt X Y\<close> if \<open>finite Y\<close> \<open>\<And>x. x \<in> X \<Longrightarrow> x > Max Y\<close>
+  using that by (auto simp add: disjnt_def) (use Max_less_iff in blast)
+
 
 subsection \<open>Arg Min\<close>
 
 context ord
 begin
 
 definition is_arg_min :: "('b \<Rightarrow> 'a) \<Rightarrow> ('b \<Rightarrow> bool) \<Rightarrow> 'b \<Rightarrow> bool" where
 "is_arg_min f P x = (P x \<and> \<not>(\<exists>y. P y \<and> f y < f x))"
 
 definition arg_min :: "('b \<Rightarrow> 'a) \<Rightarrow> ('b \<Rightarrow> bool) \<Rightarrow> 'b" where
 "arg_min f P = (SOME x. is_arg_min f P x)"
 
 definition arg_min_on :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'b" where
 "arg_min_on f S = arg_min f (\<lambda>x. x \<in> S)"
 
 end
 
 syntax
   "_arg_min" :: "('b \<Rightarrow> 'a) \<Rightarrow> pttrn \<Rightarrow> bool \<Rightarrow> 'b"
     ("(3ARG'_MIN _ _./ _)" [1000, 0, 10] 10)
 translations
   "ARG_MIN f x. P" \<rightleftharpoons> "CONST arg_min f (\<lambda>x. P)"
 
 lemma is_arg_min_linorder: fixes f :: "'a \<Rightarrow> 'b :: linorder"
 shows "is_arg_min f P x = (P x \<and> (\<forall>y. P y \<longrightarrow> f x \<le> f y))"
 by(auto simp add: is_arg_min_def)
 
 lemma is_arg_min_antimono: fixes f :: "'a \<Rightarrow> ('b::order)"
 shows "\<lbrakk> is_arg_min f P x; f y \<le> f x; P y \<rbrakk> \<Longrightarrow> is_arg_min f P y"
 by (simp add: order.order_iff_strict is_arg_min_def)
 
 lemma arg_minI:
   "\<lbrakk> P x;
     \<And>y. P y \<Longrightarrow> \<not> f y < f x;
     \<And>x. \<lbrakk> P x; \<forall>y. P y \<longrightarrow> \<not> f y < f x \<rbrakk> \<Longrightarrow> Q x \<rbrakk>
   \<Longrightarrow> Q (arg_min f P)"
 apply (simp add: arg_min_def is_arg_min_def)
 apply (rule someI2_ex)
  apply blast
 apply blast
 done
 
 lemma arg_min_equality:
   "\<lbrakk> P k; \<And>x. P x \<Longrightarrow> f k \<le> f x \<rbrakk> \<Longrightarrow> f (arg_min f P) = f k"
   for f :: "_ \<Rightarrow> 'a::order"
 apply (rule arg_minI)
   apply assumption
  apply (simp add: less_le_not_le)
 by (metis le_less)
 
 lemma wf_linord_ex_has_least:
   "\<lbrakk> wf r; \<forall>x y. (x, y) \<in> r\<^sup>+ \<longleftrightarrow> (y, x) \<notin> r\<^sup>*; P k \<rbrakk>
    \<Longrightarrow> \<exists>x. P x \<and> (\<forall>y. P y \<longrightarrow> (m x, m y) \<in> r\<^sup>*)"
 apply (drule wf_trancl [THEN wf_eq_minimal [THEN iffD1]])
 apply (drule_tac x = "m ` Collect P" in spec)
 by force
 
 lemma ex_has_least_nat: "P k \<Longrightarrow> \<exists>x. P x \<and> (\<forall>y. P y \<longrightarrow> m x \<le> m y)"
   for m :: "'a \<Rightarrow> nat"
 apply (simp only: pred_nat_trancl_eq_le [symmetric])
 apply (rule wf_pred_nat [THEN wf_linord_ex_has_least])
  apply (simp add: less_eq linorder_not_le pred_nat_trancl_eq_le)
 by assumption
 
 lemma arg_min_nat_lemma:
   "P k \<Longrightarrow> P(arg_min m P) \<and> (\<forall>y. P y \<longrightarrow> m (arg_min m P) \<le> m y)"
   for m :: "'a \<Rightarrow> nat"
 apply (simp add: arg_min_def is_arg_min_linorder)
 apply (rule someI_ex)
 apply (erule ex_has_least_nat)
 done
 
 lemmas arg_min_natI = arg_min_nat_lemma [THEN conjunct1]
 
 lemma is_arg_min_arg_min_nat: fixes m :: "'a \<Rightarrow> nat"
 shows "P x \<Longrightarrow> is_arg_min m P (arg_min m P)"
 by (metis arg_min_nat_lemma is_arg_min_linorder)
 
 lemma arg_min_nat_le: "P x \<Longrightarrow> m (arg_min m P) \<le> m x"
   for m :: "'a \<Rightarrow> nat"
 by (rule arg_min_nat_lemma [THEN conjunct2, THEN spec, THEN mp])
 
 lemma ex_min_if_finite:
   "\<lbrakk> finite S; S \<noteq> {} \<rbrakk> \<Longrightarrow> \<exists>m\<in>S. \<not>(\<exists>x\<in>S. x < (m::'a::order))"
 by(induction rule: finite.induct) (auto intro: order.strict_trans)
 
 lemma ex_is_arg_min_if_finite: fixes f :: "'a \<Rightarrow> 'b :: order"
 shows "\<lbrakk> finite S; S \<noteq> {} \<rbrakk> \<Longrightarrow> \<exists>x. is_arg_min f (\<lambda>x. x \<in> S) x"
 unfolding is_arg_min_def
 using ex_min_if_finite[of "f ` S"]
 by auto
 
 lemma arg_min_SOME_Min:
   "finite S \<Longrightarrow> arg_min_on f S = (SOME y. y \<in> S \<and> f y = Min(f ` S))"
 unfolding arg_min_on_def arg_min_def is_arg_min_linorder
 apply(rule arg_cong[where f = Eps])
 apply (auto simp: fun_eq_iff intro: Min_eqI[symmetric])
 done
 
 lemma arg_min_if_finite: fixes f :: "'a \<Rightarrow> 'b :: order"
 assumes "finite S" "S \<noteq> {}"
 shows  "arg_min_on f S \<in> S" and "\<not>(\<exists>x\<in>S. f x < f (arg_min_on f S))"
 using ex_is_arg_min_if_finite[OF assms, of f]
 unfolding arg_min_on_def arg_min_def is_arg_min_def
 by(auto dest!: someI_ex)
 
 lemma arg_min_least: fixes f :: "'a \<Rightarrow> 'b :: linorder"
 shows "\<lbrakk> finite S;  S \<noteq> {};  y \<in> S \<rbrakk> \<Longrightarrow> f(arg_min_on f S) \<le> f y"
 by(simp add: arg_min_SOME_Min inv_into_def2[symmetric] f_inv_into_f)
 
 lemma arg_min_inj_eq: fixes f :: "'a \<Rightarrow> 'b :: order"
 shows "\<lbrakk> inj_on f {x. P x}; P a; \<forall>y. P y \<longrightarrow> f a \<le> f y \<rbrakk> \<Longrightarrow> arg_min f P = a"
 apply(simp add: arg_min_def is_arg_min_def)
 apply(rule someI2[of _ a])
  apply (simp add: less_le_not_le)
 by (metis inj_on_eq_iff less_le mem_Collect_eq)
 
 
 subsection \<open>Arg Max\<close>
 
 context ord
 begin
 
 definition is_arg_max :: "('b \<Rightarrow> 'a) \<Rightarrow> ('b \<Rightarrow> bool) \<Rightarrow> 'b \<Rightarrow> bool" where
 "is_arg_max f P x = (P x \<and> \<not>(\<exists>y. P y \<and> f y > f x))"
 
 definition arg_max :: "('b \<Rightarrow> 'a) \<Rightarrow> ('b \<Rightarrow> bool) \<Rightarrow> 'b" where
 "arg_max f P = (SOME x. is_arg_max f P x)"
 
 definition arg_max_on :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'b" where
 "arg_max_on f S = arg_max f (\<lambda>x. x \<in> S)"
 
 end
 
 syntax
   "_arg_max" :: "('b \<Rightarrow> 'a) \<Rightarrow> pttrn \<Rightarrow> bool \<Rightarrow> 'a"
     ("(3ARG'_MAX _ _./ _)" [1000, 0, 10] 10)
 translations
   "ARG_MAX f x. P" \<rightleftharpoons> "CONST arg_max f (\<lambda>x. P)"
 
 lemma is_arg_max_linorder: fixes f :: "'a \<Rightarrow> 'b :: linorder"
 shows "is_arg_max f P x = (P x \<and> (\<forall>y. P y \<longrightarrow> f x \<ge> f y))"
 by(auto simp add: is_arg_max_def)
 
 lemma arg_maxI:
   "P x \<Longrightarrow>
     (\<And>y. P y \<Longrightarrow> \<not> f y > f x) \<Longrightarrow>
     (\<And>x. P x \<Longrightarrow> \<forall>y. P y \<longrightarrow> \<not> f y > f x \<Longrightarrow> Q x) \<Longrightarrow>
     Q (arg_max f P)"
 apply (simp add: arg_max_def is_arg_max_def)
 apply (rule someI2_ex)
  apply blast
 apply blast
 done
 
 lemma arg_max_equality:
   "\<lbrakk> P k; \<And>x. P x \<Longrightarrow> f x \<le> f k \<rbrakk> \<Longrightarrow> f (arg_max f P) = f k"
   for f :: "_ \<Rightarrow> 'a::order"
 apply (rule arg_maxI [where f = f])
   apply assumption
  apply (simp add: less_le_not_le)
 by (metis le_less)
 
 lemma ex_has_greatest_nat_lemma:
   "P k \<Longrightarrow> \<forall>x. P x \<longrightarrow> (\<exists>y. P y \<and> \<not> f y \<le> f x) \<Longrightarrow> \<exists>y. P y \<and> \<not> f y < f k + n"
   for f :: "'a \<Rightarrow> nat"
 by (induct n) (force simp: le_Suc_eq)+
 
 lemma ex_has_greatest_nat:
   "P k \<Longrightarrow> \<forall>y. P y \<longrightarrow> f y < b \<Longrightarrow> \<exists>x. P x \<and> (\<forall>y. P y \<longrightarrow> f y \<le> f x)"
   for f :: "'a \<Rightarrow> nat"
 apply (rule ccontr)
 apply (cut_tac P = P and n = "b - f k" in ex_has_greatest_nat_lemma)
   apply (subgoal_tac [3] "f k \<le> b")
    apply auto
 done
 
 lemma arg_max_nat_lemma:
   "\<lbrakk> P k;  \<forall>y. P y \<longrightarrow> f y < b \<rbrakk>
   \<Longrightarrow> P (arg_max f P) \<and> (\<forall>y. P y \<longrightarrow> f y \<le> f (arg_max f P))"
   for f :: "'a \<Rightarrow> nat"
 apply (simp add: arg_max_def is_arg_max_linorder)
 apply (rule someI_ex)
 apply (erule (1) ex_has_greatest_nat)
 done
 
 lemmas arg_max_natI = arg_max_nat_lemma [THEN conjunct1]
 
 lemma arg_max_nat_le: "P x \<Longrightarrow> \<forall>y. P y \<longrightarrow> f y < b \<Longrightarrow> f x \<le> f (arg_max f P)"
   for f :: "'a \<Rightarrow> nat"
 by (blast dest: arg_max_nat_lemma [THEN conjunct2, THEN spec, of P])
 
 end
diff --git a/src/HOL/Library/Disjoint_FSets.thy b/src/HOL/Library/Disjoint_FSets.thy
new file mode 100644
--- /dev/null
+++ b/src/HOL/Library/Disjoint_FSets.thy
@@ -0,0 +1,72 @@
+(*  Title:      HOL/Library/Disjoint_FSets.thy
+    Author:     Lars Hupel, TU München
+*)
+
+section \<open>Disjoint FSets\<close>
+
+theory Disjoint_FSets
+  imports
+    "HOL-Library.Finite_Map"
+    "HOL-Library.Disjoint_Sets"
+begin
+
+context
+  includes fset.lifting
+begin
+
+lift_definition fdisjnt :: "'a fset \<Rightarrow> 'a fset \<Rightarrow> bool" is disjnt .
+
+lemma fdisjnt_alt_def: "fdisjnt M N \<longleftrightarrow> (M |\<inter>| N = {||})"
+by transfer (simp add: disjnt_def)
+
+lemma fdisjnt_insert: "x |\<notin>| N \<Longrightarrow> fdisjnt M N \<Longrightarrow> fdisjnt (finsert x M) N"
+by transfer' (rule disjnt_insert)
+
+lemma fdisjnt_subset_right: "N' |\<subseteq>| N \<Longrightarrow> fdisjnt M N \<Longrightarrow> fdisjnt M N'"
+unfolding fdisjnt_alt_def by auto
+
+lemma fdisjnt_subset_left: "N' |\<subseteq>| N \<Longrightarrow> fdisjnt N M \<Longrightarrow> fdisjnt N' M"
+unfolding fdisjnt_alt_def by auto
+
+lemma fdisjnt_union_right: "fdisjnt M A \<Longrightarrow> fdisjnt M B \<Longrightarrow> fdisjnt M (A |\<union>| B)"
+unfolding fdisjnt_alt_def by auto
+
+lemma fdisjnt_union_left: "fdisjnt A M \<Longrightarrow> fdisjnt B M \<Longrightarrow> fdisjnt (A |\<union>| B) M"
+unfolding fdisjnt_alt_def by auto
+
+lemma fdisjnt_swap: "fdisjnt M N \<Longrightarrow> fdisjnt N M"
+including fset.lifting by transfer' (auto simp: disjnt_def)
+
+lemma distinct_append_fset:
+  assumes "distinct xs" "distinct ys" "fdisjnt (fset_of_list xs) (fset_of_list ys)"
+  shows "distinct (xs @ ys)"
+using assms
+by transfer' (simp add: disjnt_def)
+
+lemma fdisjnt_contrI:
+  assumes "\<And>x. x |\<in>| M \<Longrightarrow> x |\<in>| N \<Longrightarrow> False"
+  shows "fdisjnt M N"
+using assms
+by transfer' (auto simp: disjnt_def)
+
+lemma fdisjnt_Union_left: "fdisjnt (ffUnion S) T \<longleftrightarrow> fBall S (\<lambda>S. fdisjnt S T)"
+by transfer' (auto simp: disjnt_def)
+
+lemma fdisjnt_Union_right: "fdisjnt T (ffUnion S) \<longleftrightarrow> fBall S (\<lambda>S. fdisjnt T S)"
+by transfer' (auto simp: disjnt_def)
+
+lemma fdisjnt_ge_max: "fBall X (\<lambda>x. x > fMax Y) \<Longrightarrow> fdisjnt X Y"
+by transfer (auto intro: disjnt_ge_max)
+
+end
+
+(* FIXME should be provable without lifting *)
+lemma fmadd_disjnt: "fdisjnt (fmdom m) (fmdom n) \<Longrightarrow> m ++\<^sub>f n = n ++\<^sub>f m"
+unfolding fdisjnt_alt_def
+including fset.lifting fmap.lifting
+apply transfer
+apply (rule ext)
+apply (auto simp: map_add_def split: option.splits)
+done
+
+end
diff --git a/src/HOL/Library/Library.thy b/src/HOL/Library/Library.thy
--- a/src/HOL/Library/Library.thy
+++ b/src/HOL/Library/Library.thy
@@ -1,106 +1,107 @@
 (*<*)
 theory Library
 imports
   AList
   Adhoc_Overloading
   BigO
   Bit_Operations
   BNF_Axiomatization
   BNF_Corec
   Boolean_Algebra
   Bourbaki_Witt_Fixpoint
   Char_ord
   Code_Lazy
   Code_Test
   Combine_PER
   Complete_Partial_Order2
   Conditional_Parametricity
   Confluence
   Confluent_Quotient
   Countable
   Countable_Complete_Lattices
   Countable_Set_Type
   Debug
   Diagonal_Subsequence
   Discrete
   Disjoint_Sets
+  Disjoint_FSets
   Dlist
   Dual_Ordered_Lattice
   Equipollence
   Extended
   Extended_Nat
   Extended_Nonnegative_Real
   Extended_Real
   Finite_Map
   Float
   FSet
   FuncSet
   Function_Division
   Fun_Lexorder
   Going_To_Filter
   Groups_Big_Fun
   Indicator_Function
   Infinite_Set
   Interval
   Interval_Float
   IArray
   Landau_Symbols
   Lattice_Algebras
   Lattice_Syntax
   Lattice_Constructions
   Linear_Temporal_Logic_on_Streams
   ListVector
   List_Permutation
   Lub_Glb
   Mapping
   Monad_Syntax
   More_List
   Multiset_Order
   Multiset_Permutations
   Nonpos_Ints
   Numeral_Type
   Omega_Words_Fun
   Open_State_Syntax
   Option_ord
   Order_Continuity
   Parallel
   Pattern_Aliases
   Periodic_Fun
   Perm
   Permutations
   Poly_Mapping
   Power_By_Squaring
   Preorder
   Product_Plus
   Quadratic_Discriminant
   Quotient_List
   Quotient_Option
   Quotient_Product
   Quotient_Set
   Quotient_Sum
   Quotient_Syntax
   Quotient_Type
   Ramsey
   Reflection
   Rewrite
   Saturated
   Set_Algebras
   Set_Idioms
   Signed_Division
   State_Monad
   Stirling
   Stream
   Sorting_Algorithms
   Sublist
   Sum_of_Squares
   Transitive_Closure_Table
   Tree_Multiset
   Tree_Real
   Type_Length
   Uprod
   While_Combinator
   Word
   Z2
 begin
 end
 (*>*)
diff --git a/src/HOL/Set.thy b/src/HOL/Set.thy
--- a/src/HOL/Set.thy
+++ b/src/HOL/Set.thy
@@ -1,2034 +1,2038 @@
 (*  Title:      HOL/Set.thy
     Author:     Tobias Nipkow
     Author:     Lawrence C Paulson
     Author:     Markus Wenzel
 *)
 
 section \<open>Set theory for higher-order logic\<close>
 
 theory Set
   imports Lattices
 begin
 
 subsection \<open>Sets as predicates\<close>
 
 typedecl 'a set
 
 axiomatization Collect :: "('a \<Rightarrow> bool) \<Rightarrow> 'a set" \<comment> \<open>comprehension\<close>
   and member :: "'a \<Rightarrow> 'a set \<Rightarrow> bool" \<comment> \<open>membership\<close>
   where mem_Collect_eq [iff, code_unfold]: "member a (Collect P) = P a"
     and Collect_mem_eq [simp]: "Collect (\<lambda>x. member x A) = A"
 
 notation
   member  ("'(\<in>')") and
   member  ("(_/ \<in> _)" [51, 51] 50)
 
 abbreviation not_member
   where "not_member x A \<equiv> \<not> (x \<in> A)" \<comment> \<open>non-membership\<close>
 notation
   not_member  ("'(\<notin>')") and
   not_member  ("(_/ \<notin> _)" [51, 51] 50)
 
 notation (ASCII)
   member  ("'(:')") and
   member  ("(_/ : _)" [51, 51] 50) and
   not_member  ("'(~:')") and
   not_member  ("(_/ ~: _)" [51, 51] 50)
 
 
 text \<open>Set comprehensions\<close>
 
 syntax
   "_Coll" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a set"    ("(1{_./ _})")
 translations
   "{x. P}" \<rightleftharpoons> "CONST Collect (\<lambda>x. P)"
 
 syntax (ASCII)
   "_Collect" :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> 'a set"  ("(1{(_/: _)./ _})")
 syntax
   "_Collect" :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> 'a set"  ("(1{(_/ \<in> _)./ _})")
 translations
   "{p:A. P}" \<rightharpoonup> "CONST Collect (\<lambda>p. p \<in> A \<and> P)"
 
 lemma CollectI: "P a \<Longrightarrow> a \<in> {x. P x}"
   by simp
 
 lemma CollectD: "a \<in> {x. P x} \<Longrightarrow> P a"
   by simp
 
 lemma Collect_cong: "(\<And>x. P x = Q x) \<Longrightarrow> {x. P x} = {x. Q x}"
   by simp
 
 text \<open>
   Simproc for pulling \<open>x = t\<close> in \<open>{x. \<dots> \<and> x = t \<and> \<dots>}\<close>
   to the front (and similarly for \<open>t = x\<close>):
 \<close>
 
 simproc_setup defined_Collect ("{x. P x \<and> Q x}") = \<open>
   fn _ => Quantifier1.rearrange_Collect
     (fn ctxt =>
       resolve_tac ctxt @{thms Collect_cong} 1 THEN
       resolve_tac ctxt @{thms iffI} 1 THEN
       ALLGOALS
         (EVERY' [REPEAT_DETERM o eresolve_tac ctxt @{thms conjE},
           DEPTH_SOLVE_1 o (assume_tac ctxt ORELSE' resolve_tac ctxt @{thms conjI})]))
 \<close>
 
 lemmas CollectE = CollectD [elim_format]
 
 lemma set_eqI:
   assumes "\<And>x. x \<in> A \<longleftrightarrow> x \<in> B"
   shows "A = B"
 proof -
   from assms have "{x. x \<in> A} = {x. x \<in> B}"
     by simp
   then show ?thesis by simp
 qed
 
 lemma set_eq_iff: "A = B \<longleftrightarrow> (\<forall>x. x \<in> A \<longleftrightarrow> x \<in> B)"
   by (auto intro:set_eqI)
 
 lemma Collect_eqI:
   assumes "\<And>x. P x = Q x"
   shows "Collect P = Collect Q"
   using assms by (auto intro: set_eqI)
 
 text \<open>Lifting of predicate class instances\<close>
 
 instantiation set :: (type) boolean_algebra
 begin
 
 definition less_eq_set
   where "A \<le> B \<longleftrightarrow> (\<lambda>x. member x A) \<le> (\<lambda>x. member x B)"
 
 definition less_set
   where "A < B \<longleftrightarrow> (\<lambda>x. member x A) < (\<lambda>x. member x B)"
 
 definition inf_set
   where "A \<sqinter> B = Collect ((\<lambda>x. member x A) \<sqinter> (\<lambda>x. member x B))"
 
 definition sup_set
   where "A \<squnion> B = Collect ((\<lambda>x. member x A) \<squnion> (\<lambda>x. member x B))"
 
 definition bot_set
   where "\<bottom> = Collect \<bottom>"
 
 definition top_set
   where "\<top> = Collect \<top>"
 
 definition uminus_set
   where "- A = Collect (- (\<lambda>x. member x A))"
 
 definition minus_set
   where "A - B = Collect ((\<lambda>x. member x A) - (\<lambda>x. member x B))"
 
 instance
   by standard
     (simp_all add: less_eq_set_def less_set_def inf_set_def sup_set_def
       bot_set_def top_set_def uminus_set_def minus_set_def
       less_le_not_le sup_inf_distrib1 diff_eq set_eqI fun_eq_iff
       del: inf_apply sup_apply bot_apply top_apply minus_apply uminus_apply)
 
 end
 
 text \<open>Set enumerations\<close>
 
 abbreviation empty :: "'a set" ("{}")
   where "{} \<equiv> bot"
 
 definition insert :: "'a \<Rightarrow> 'a set \<Rightarrow> 'a set"
   where insert_compr: "insert a B = {x. x = a \<or> x \<in> B}"
 
 syntax
   "_Finset" :: "args \<Rightarrow> 'a set"    ("{(_)}")
 translations
   "{x, xs}" \<rightleftharpoons> "CONST insert x {xs}"
   "{x}" \<rightleftharpoons> "CONST insert x {}"
 
 
 subsection \<open>Subsets and bounded quantifiers\<close>
 
 abbreviation subset :: "'a set \<Rightarrow> 'a set \<Rightarrow> bool"
   where "subset \<equiv> less"
 
 abbreviation subset_eq :: "'a set \<Rightarrow> 'a set \<Rightarrow> bool"
   where "subset_eq \<equiv> less_eq"
 
 notation
   subset  ("'(\<subset>')") and
   subset  ("(_/ \<subset> _)" [51, 51] 50) and
   subset_eq  ("'(\<subseteq>')") and
   subset_eq  ("(_/ \<subseteq> _)" [51, 51] 50)
 
 abbreviation (input)
   supset :: "'a set \<Rightarrow> 'a set \<Rightarrow> bool" where
   "supset \<equiv> greater"
 
 abbreviation (input)
   supset_eq :: "'a set \<Rightarrow> 'a set \<Rightarrow> bool" where
   "supset_eq \<equiv> greater_eq"
 
 notation
   supset  ("'(\<supset>')") and
   supset  ("(_/ \<supset> _)" [51, 51] 50) and
   supset_eq  ("'(\<supseteq>')") and
   supset_eq  ("(_/ \<supseteq> _)" [51, 51] 50)
 
 notation (ASCII output)
   subset  ("'(<')") and
   subset  ("(_/ < _)" [51, 51] 50) and
   subset_eq  ("'(<=')") and
   subset_eq  ("(_/ <= _)" [51, 51] 50)
 
 definition Ball :: "'a set \<Rightarrow> ('a \<Rightarrow> bool) \<Rightarrow> bool"
   where "Ball A P \<longleftrightarrow> (\<forall>x. x \<in> A \<longrightarrow> P x)"   \<comment> \<open>bounded universal quantifiers\<close>
 
 definition Bex :: "'a set \<Rightarrow> ('a \<Rightarrow> bool) \<Rightarrow> bool"
   where "Bex A P \<longleftrightarrow> (\<exists>x. x \<in> A \<and> P x)"   \<comment> \<open>bounded existential quantifiers\<close>
 
 syntax (ASCII)
   "_Ball"       :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3ALL (_/:_)./ _)" [0, 0, 10] 10)
   "_Bex"        :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3EX (_/:_)./ _)" [0, 0, 10] 10)
   "_Bex1"       :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3EX! (_/:_)./ _)" [0, 0, 10] 10)
   "_Bleast"     :: "id \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> 'a"           ("(3LEAST (_/:_)./ _)" [0, 0, 10] 10)
 
 syntax (input)
   "_Ball"       :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3! (_/:_)./ _)" [0, 0, 10] 10)
   "_Bex"        :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3? (_/:_)./ _)" [0, 0, 10] 10)
   "_Bex1"       :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3?! (_/:_)./ _)" [0, 0, 10] 10)
 
 syntax
   "_Ball"       :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3\<forall>(_/\<in>_)./ _)" [0, 0, 10] 10)
   "_Bex"        :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3\<exists>(_/\<in>_)./ _)" [0, 0, 10] 10)
   "_Bex1"       :: "pttrn \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> bool"      ("(3\<exists>!(_/\<in>_)./ _)" [0, 0, 10] 10)
   "_Bleast"     :: "id \<Rightarrow> 'a set \<Rightarrow> bool \<Rightarrow> 'a"           ("(3LEAST(_/\<in>_)./ _)" [0, 0, 10] 10)
 
 translations
   "\<forall>x\<in>A. P" \<rightleftharpoons> "CONST Ball A (\<lambda>x. P)"
   "\<exists>x\<in>A. P" \<rightleftharpoons> "CONST Bex A (\<lambda>x. P)"
   "\<exists>!x\<in>A. P" \<rightharpoonup> "\<exists>!x. x \<in> A \<and> P"
   "LEAST x:A. P" \<rightharpoonup> "LEAST x. x \<in> A \<and> P"
 
 syntax (ASCII output)
   "_setlessAll" :: "[idt, 'a, bool] \<Rightarrow> bool"  ("(3ALL _<_./ _)"  [0, 0, 10] 10)
   "_setlessEx"  :: "[idt, 'a, bool] \<Rightarrow> bool"  ("(3EX _<_./ _)"  [0, 0, 10] 10)
   "_setleAll"   :: "[idt, 'a, bool] \<Rightarrow> bool"  ("(3ALL _<=_./ _)" [0, 0, 10] 10)
   "_setleEx"    :: "[idt, 'a, bool] \<Rightarrow> bool"  ("(3EX _<=_./ _)" [0, 0, 10] 10)
   "_setleEx1"   :: "[idt, 'a, bool] \<Rightarrow> bool"  ("(3EX! _<=_./ _)" [0, 0, 10] 10)
 
 syntax
   "_setlessAll" :: "[idt, 'a, bool] \<Rightarrow> bool"   ("(3\<forall>_\<subset>_./ _)"  [0, 0, 10] 10)
   "_setlessEx"  :: "[idt, 'a, bool] \<Rightarrow> bool"   ("(3\<exists>_\<subset>_./ _)"  [0, 0, 10] 10)
   "_setleAll"   :: "[idt, 'a, bool] \<Rightarrow> bool"   ("(3\<forall>_\<subseteq>_./ _)" [0, 0, 10] 10)
   "_setleEx"    :: "[idt, 'a, bool] \<Rightarrow> bool"   ("(3\<exists>_\<subseteq>_./ _)" [0, 0, 10] 10)
   "_setleEx1"   :: "[idt, 'a, bool] \<Rightarrow> bool"   ("(3\<exists>!_\<subseteq>_./ _)" [0, 0, 10] 10)
 
 translations
  "\<forall>A\<subset>B. P" \<rightharpoonup> "\<forall>A. A \<subset> B \<longrightarrow> P"
  "\<exists>A\<subset>B. P" \<rightharpoonup> "\<exists>A. A \<subset> B \<and> P"
  "\<forall>A\<subseteq>B. P" \<rightharpoonup> "\<forall>A. A \<subseteq> B \<longrightarrow> P"
  "\<exists>A\<subseteq>B. P" \<rightharpoonup> "\<exists>A. A \<subseteq> B \<and> P"
  "\<exists>!A\<subseteq>B. P" \<rightharpoonup> "\<exists>!A. A \<subseteq> B \<and> P"
 
 print_translation \<open>
   let
     val All_binder = Mixfix.binder_name \<^const_syntax>\<open>All\<close>;
     val Ex_binder = Mixfix.binder_name \<^const_syntax>\<open>Ex\<close>;
     val impl = \<^const_syntax>\<open>HOL.implies\<close>;
     val conj = \<^const_syntax>\<open>HOL.conj\<close>;
     val sbset = \<^const_syntax>\<open>subset\<close>;
     val sbset_eq = \<^const_syntax>\<open>subset_eq\<close>;
 
     val trans =
      [((All_binder, impl, sbset), \<^syntax_const>\<open>_setlessAll\<close>),
       ((All_binder, impl, sbset_eq), \<^syntax_const>\<open>_setleAll\<close>),
       ((Ex_binder, conj, sbset), \<^syntax_const>\<open>_setlessEx\<close>),
       ((Ex_binder, conj, sbset_eq), \<^syntax_const>\<open>_setleEx\<close>)];
 
     fun mk v (v', T) c n P =
       if v = v' andalso not (Term.exists_subterm (fn Free (x, _) => x = v | _ => false) n)
       then Syntax.const c $ Syntax_Trans.mark_bound_body (v', T) $ n $ P
       else raise Match;
 
     fun tr' q = (q, fn _ =>
       (fn [Const (\<^syntax_const>\<open>_bound\<close>, _) $ Free (v, Type (\<^type_name>\<open>set\<close>, _)),
           Const (c, _) $
             (Const (d, _) $ (Const (\<^syntax_const>\<open>_bound\<close>, _) $ Free (v', T)) $ n) $ P] =>
           (case AList.lookup (=) trans (q, c, d) of
             NONE => raise Match
           | SOME l => mk v (v', T) l n P)
         | _ => raise Match));
   in
     [tr' All_binder, tr' Ex_binder]
   end
 \<close>
 
 
 text \<open>
   \<^medskip>
   Translate between \<open>{e | x1\<dots>xn. P}\<close> and \<open>{u. \<exists>x1\<dots>xn. u = e \<and> P}\<close>;
   \<open>{y. \<exists>x1\<dots>xn. y = e \<and> P}\<close> is only translated if \<open>[0..n] \<subseteq> bvs e\<close>.
 \<close>
 
 syntax
   "_Setcompr" :: "'a \<Rightarrow> idts \<Rightarrow> bool \<Rightarrow> 'a set"    ("(1{_ |/_./ _})")
 
 parse_translation \<open>
   let
     val ex_tr = snd (Syntax_Trans.mk_binder_tr ("EX ", \<^const_syntax>\<open>Ex\<close>));
 
     fun nvars (Const (\<^syntax_const>\<open>_idts\<close>, _) $ _ $ idts) = nvars idts + 1
       | nvars _ = 1;
 
     fun setcompr_tr ctxt [e, idts, b] =
       let
         val eq = Syntax.const \<^const_syntax>\<open>HOL.eq\<close> $ Bound (nvars idts) $ e;
         val P = Syntax.const \<^const_syntax>\<open>HOL.conj\<close> $ eq $ b;
         val exP = ex_tr ctxt [idts, P];
       in Syntax.const \<^const_syntax>\<open>Collect\<close> $ absdummy dummyT exP end;
 
   in [(\<^syntax_const>\<open>_Setcompr\<close>, setcompr_tr)] end
 \<close>
 
 print_translation \<open>
  [Syntax_Trans.preserve_binder_abs2_tr' \<^const_syntax>\<open>Ball\<close> \<^syntax_const>\<open>_Ball\<close>,
   Syntax_Trans.preserve_binder_abs2_tr' \<^const_syntax>\<open>Bex\<close> \<^syntax_const>\<open>_Bex\<close>]
 \<close> \<comment> \<open>to avoid eta-contraction of body\<close>
 
 print_translation \<open>
 let
   val ex_tr' = snd (Syntax_Trans.mk_binder_tr' (\<^const_syntax>\<open>Ex\<close>, "DUMMY"));
 
   fun setcompr_tr' ctxt [Abs (abs as (_, _, P))] =
     let
       fun check (Const (\<^const_syntax>\<open>Ex\<close>, _) $ Abs (_, _, P), n) = check (P, n + 1)
         | check (Const (\<^const_syntax>\<open>HOL.conj\<close>, _) $
               (Const (\<^const_syntax>\<open>HOL.eq\<close>, _) $ Bound m $ e) $ P, n) =
             n > 0 andalso m = n andalso not (loose_bvar1 (P, n)) andalso
             subset (=) (0 upto (n - 1), add_loose_bnos (e, 0, []))
         | check _ = false;
 
         fun tr' (_ $ abs) =
           let val _ $ idts $ (_ $ (_ $ _ $ e) $ Q) = ex_tr' ctxt [abs]
           in Syntax.const \<^syntax_const>\<open>_Setcompr\<close> $ e $ idts $ Q end;
     in
       if check (P, 0) then tr' P
       else
         let
           val (x as _ $ Free(xN, _), t) = Syntax_Trans.atomic_abs_tr' abs;
           val M = Syntax.const \<^syntax_const>\<open>_Coll\<close> $ x $ t;
         in
           case t of
             Const (\<^const_syntax>\<open>HOL.conj\<close>, _) $
               (Const (\<^const_syntax>\<open>Set.member\<close>, _) $
                 (Const (\<^syntax_const>\<open>_bound\<close>, _) $ Free (yN, _)) $ A) $ P =>
             if xN = yN then Syntax.const \<^syntax_const>\<open>_Collect\<close> $ x $ A $ P else M
           | _ => M
         end
     end;
   in [(\<^const_syntax>\<open>Collect\<close>, setcompr_tr')] end
 \<close>
 
 simproc_setup defined_Bex ("\<exists>x\<in>A. P x \<and> Q x") = \<open>
   fn _ => Quantifier1.rearrange_Bex
     (fn ctxt => unfold_tac ctxt @{thms Bex_def})
 \<close>
 
 simproc_setup defined_All ("\<forall>x\<in>A. P x \<longrightarrow> Q x") = \<open>
   fn _ => Quantifier1.rearrange_Ball
     (fn ctxt => unfold_tac ctxt @{thms Ball_def})
 \<close>
 
 lemma ballI [intro!]: "(\<And>x. x \<in> A \<Longrightarrow> P x) \<Longrightarrow> \<forall>x\<in>A. P x"
   by (simp add: Ball_def)
 
 lemmas strip = impI allI ballI
 
 lemma bspec [dest?]: "\<forall>x\<in>A. P x \<Longrightarrow> x \<in> A \<Longrightarrow> P x"
   by (simp add: Ball_def)
 
 text \<open>Gives better instantiation for bound:\<close>
 setup \<open>
   map_theory_claset (fn ctxt =>
     ctxt addbefore ("bspec", fn ctxt' => dresolve_tac ctxt' @{thms bspec} THEN' assume_tac ctxt'))
 \<close>
 
 ML \<open>
 structure Simpdata =
 struct
   open Simpdata;
   val mksimps_pairs = [(\<^const_name>\<open>Ball\<close>, @{thms bspec})] @ mksimps_pairs;
 end;
 
 open Simpdata;
 \<close>
 
 declaration \<open>fn _ => Simplifier.map_ss (Simplifier.set_mksimps (mksimps mksimps_pairs))\<close>
 
 lemma ballE [elim]: "\<forall>x\<in>A. P x \<Longrightarrow> (P x \<Longrightarrow> Q) \<Longrightarrow> (x \<notin> A \<Longrightarrow> Q) \<Longrightarrow> Q"
   unfolding Ball_def by blast
 
 lemma bexI [intro]: "P x \<Longrightarrow> x \<in> A \<Longrightarrow> \<exists>x\<in>A. P x"
   \<comment> \<open>Normally the best argument order: \<open>P x\<close> constrains the choice of \<open>x \<in> A\<close>.\<close>
   unfolding Bex_def by blast
 
 lemma rev_bexI [intro?]: "x \<in> A \<Longrightarrow> P x \<Longrightarrow> \<exists>x\<in>A. P x"
   \<comment> \<open>The best argument order when there is only one \<open>x \<in> A\<close>.\<close>
   unfolding Bex_def by blast
 
 lemma bexCI: "(\<forall>x\<in>A. \<not> P x \<Longrightarrow> P a) \<Longrightarrow> a \<in> A \<Longrightarrow> \<exists>x\<in>A. P x"
   unfolding Bex_def by blast
 
 lemma bexE [elim!]: "\<exists>x\<in>A. P x \<Longrightarrow> (\<And>x. x \<in> A \<Longrightarrow> P x \<Longrightarrow> Q) \<Longrightarrow> Q"
   unfolding Bex_def by blast
 
 lemma ball_triv [simp]: "(\<forall>x\<in>A. P) \<longleftrightarrow> ((\<exists>x. x \<in> A) \<longrightarrow> P)"
   \<comment> \<open>trivial rewrite rule.\<close>
   by (simp add: Ball_def)
 
 lemma bex_triv [simp]: "(\<exists>x\<in>A. P) \<longleftrightarrow> ((\<exists>x. x \<in> A) \<and> P)"
   \<comment> \<open>Dual form for existentials.\<close>
   by (simp add: Bex_def)
 
 lemma bex_triv_one_point1 [simp]: "(\<exists>x\<in>A. x = a) \<longleftrightarrow> a \<in> A"
   by blast
 
 lemma bex_triv_one_point2 [simp]: "(\<exists>x\<in>A. a = x) \<longleftrightarrow> a \<in> A"
   by blast
 
 lemma bex_one_point1 [simp]: "(\<exists>x\<in>A. x = a \<and> P x) \<longleftrightarrow> a \<in> A \<and> P a"
   by blast
 
 lemma bex_one_point2 [simp]: "(\<exists>x\<in>A. a = x \<and> P x) \<longleftrightarrow> a \<in> A \<and> P a"
   by blast
 
 lemma ball_one_point1 [simp]: "(\<forall>x\<in>A. x = a \<longrightarrow> P x) \<longleftrightarrow> (a \<in> A \<longrightarrow> P a)"
   by blast
 
 lemma ball_one_point2 [simp]: "(\<forall>x\<in>A. a = x \<longrightarrow> P x) \<longleftrightarrow> (a \<in> A \<longrightarrow> P a)"
   by blast
 
 lemma ball_conj_distrib: "(\<forall>x\<in>A. P x \<and> Q x) \<longleftrightarrow> (\<forall>x\<in>A. P x) \<and> (\<forall>x\<in>A. Q x)"
   by blast
 
 lemma bex_disj_distrib: "(\<exists>x\<in>A. P x \<or> Q x) \<longleftrightarrow> (\<exists>x\<in>A. P x) \<or> (\<exists>x\<in>A. Q x)"
   by blast
 
 
 text \<open>Congruence rules\<close>
 
 lemma ball_cong:
   "\<lbrakk> A = B;  \<And>x. x \<in> B \<Longrightarrow> P x \<longleftrightarrow> Q x \<rbrakk> \<Longrightarrow>
     (\<forall>x\<in>A. P x) \<longleftrightarrow> (\<forall>x\<in>B. Q x)"
 by (simp add: Ball_def)
 
 lemma ball_cong_simp [cong]:
   "\<lbrakk> A = B;  \<And>x. x \<in> B =simp=> P x \<longleftrightarrow> Q x \<rbrakk> \<Longrightarrow>
     (\<forall>x\<in>A. P x) \<longleftrightarrow> (\<forall>x\<in>B. Q x)"
 by (simp add: simp_implies_def Ball_def)
 
 lemma bex_cong:
   "\<lbrakk> A = B;  \<And>x. x \<in> B \<Longrightarrow> P x \<longleftrightarrow> Q x \<rbrakk> \<Longrightarrow>
     (\<exists>x\<in>A. P x) \<longleftrightarrow> (\<exists>x\<in>B. Q x)"
 by (simp add: Bex_def cong: conj_cong)
 
 lemma bex_cong_simp [cong]:
   "\<lbrakk> A = B;  \<And>x. x \<in> B =simp=> P x \<longleftrightarrow> Q x \<rbrakk> \<Longrightarrow>
     (\<exists>x\<in>A. P x) \<longleftrightarrow> (\<exists>x\<in>B. Q x)"
 by (simp add: simp_implies_def Bex_def cong: conj_cong)
 
 lemma bex1_def: "(\<exists>!x\<in>X. P x) \<longleftrightarrow> (\<exists>x\<in>X. P x) \<and> (\<forall>x\<in>X. \<forall>y\<in>X. P x \<longrightarrow> P y \<longrightarrow> x = y)"
   by auto
 
 
 subsection \<open>Basic operations\<close>
 
 subsubsection \<open>Subsets\<close>
 
 lemma subsetI [intro!]: "(\<And>x. x \<in> A \<Longrightarrow> x \<in> B) \<Longrightarrow> A \<subseteq> B"
   by (simp add: less_eq_set_def le_fun_def)
 
 text \<open>
   \<^medskip>
   Map the type \<open>'a set \<Rightarrow> anything\<close> to just \<open>'a\<close>; for overloading constants
   whose first argument has type \<open>'a set\<close>.
 \<close>
 
 lemma subsetD [elim, intro?]: "A \<subseteq> B \<Longrightarrow> c \<in> A \<Longrightarrow> c \<in> B"
   by (simp add: less_eq_set_def le_fun_def)
   \<comment> \<open>Rule in Modus Ponens style.\<close>
 
 lemma rev_subsetD [intro?,no_atp]: "c \<in> A \<Longrightarrow> A \<subseteq> B \<Longrightarrow> c \<in> B"
   \<comment> \<open>The same, with reversed premises for use with @{method erule} -- cf. @{thm rev_mp}.\<close>
   by (rule subsetD)
 
 lemma subsetCE [elim,no_atp]: "A \<subseteq> B \<Longrightarrow> (c \<notin> A \<Longrightarrow> P) \<Longrightarrow> (c \<in> B \<Longrightarrow> P) \<Longrightarrow> P"
   \<comment> \<open>Classical elimination rule.\<close>
   by (auto simp add: less_eq_set_def le_fun_def)
 
 lemma subset_eq: "A \<subseteq> B \<longleftrightarrow> (\<forall>x\<in>A. x \<in> B)"
   by blast
 
 lemma contra_subsetD [no_atp]: "A \<subseteq> B \<Longrightarrow> c \<notin> B \<Longrightarrow> c \<notin> A"
   by blast
 
 lemma subset_refl: "A \<subseteq> A"
   by (fact order_refl) (* already [iff] *)
 
 lemma subset_trans: "A \<subseteq> B \<Longrightarrow> B \<subseteq> C \<Longrightarrow> A \<subseteq> C"
   by (fact order_trans)
 
 lemma subset_not_subset_eq [code]: "A \<subset> B \<longleftrightarrow> A \<subseteq> B \<and> \<not> B \<subseteq> A"
   by (fact less_le_not_le)
 
 lemma eq_mem_trans: "a = b \<Longrightarrow> b \<in> A \<Longrightarrow> a \<in> A"
   by simp
 
 lemmas basic_trans_rules [trans] =
   order_trans_rules rev_subsetD subsetD eq_mem_trans
 
 
 subsubsection \<open>Equality\<close>
 
 lemma subset_antisym [intro!]: "A \<subseteq> B \<Longrightarrow> B \<subseteq> A \<Longrightarrow> A = B"
   \<comment> \<open>Anti-symmetry of the subset relation.\<close>
   by (iprover intro: set_eqI subsetD)
 
 text \<open>\<^medskip> Equality rules from ZF set theory -- are they appropriate here?\<close>
 
 lemma equalityD1: "A = B \<Longrightarrow> A \<subseteq> B"
   by simp
 
 lemma equalityD2: "A = B \<Longrightarrow> B \<subseteq> A"
   by simp
 
 text \<open>
   \<^medskip>
   Be careful when adding this to the claset as \<open>subset_empty\<close> is in the
   simpset: \<^prop>\<open>A = {}\<close> goes to \<^prop>\<open>{} \<subseteq> A\<close> and \<^prop>\<open>A \<subseteq> {}\<close>
   and then back to \<^prop>\<open>A = {}\<close>!
 \<close>
 
 lemma equalityE: "A = B \<Longrightarrow> (A \<subseteq> B \<Longrightarrow> B \<subseteq> A \<Longrightarrow> P) \<Longrightarrow> P"
   by simp
 
 lemma equalityCE [elim]: "A = B \<Longrightarrow> (c \<in> A \<Longrightarrow> c \<in> B \<Longrightarrow> P) \<Longrightarrow> (c \<notin> A \<Longrightarrow> c \<notin> B \<Longrightarrow> P) \<Longrightarrow> P"
   by blast
 
 lemma eqset_imp_iff: "A = B \<Longrightarrow> x \<in> A \<longleftrightarrow> x \<in> B"
   by simp
 
 lemma eqelem_imp_iff: "x = y \<Longrightarrow> x \<in> A \<longleftrightarrow> y \<in> A"
   by simp
 
 
 subsubsection \<open>The empty set\<close>
 
 lemma empty_def: "{} = {x. False}"
   by (simp add: bot_set_def bot_fun_def)
 
 lemma empty_iff [simp]: "c \<in> {} \<longleftrightarrow> False"
   by (simp add: empty_def)
 
 lemma emptyE [elim!]: "a \<in> {} \<Longrightarrow> P"
   by simp
 
 lemma empty_subsetI [iff]: "{} \<subseteq> A"
   \<comment> \<open>One effect is to delete the ASSUMPTION \<^prop>\<open>{} \<subseteq> A\<close>\<close>
   by blast
 
 lemma equals0I: "(\<And>y. y \<in> A \<Longrightarrow> False) \<Longrightarrow> A = {}"
   by blast
 
 lemma equals0D: "A = {} \<Longrightarrow> a \<notin> A"
   \<comment> \<open>Use for reasoning about disjointness: \<open>A \<inter> B = {}\<close>\<close>
   by blast
 
 lemma ball_empty [simp]: "Ball {} P \<longleftrightarrow> True"
   by (simp add: Ball_def)
 
 lemma bex_empty [simp]: "Bex {} P \<longleftrightarrow> False"
   by (simp add: Bex_def)
 
 
 subsubsection \<open>The universal set -- UNIV\<close>
 
 abbreviation UNIV :: "'a set"
   where "UNIV \<equiv> top"
 
 lemma UNIV_def: "UNIV = {x. True}"
   by (simp add: top_set_def top_fun_def)
 
 lemma UNIV_I [simp]: "x \<in> UNIV"
   by (simp add: UNIV_def)
 
 declare UNIV_I [intro]  \<comment> \<open>unsafe makes it less likely to cause problems\<close>
 
 lemma UNIV_witness [intro?]: "\<exists>x. x \<in> UNIV"
   by simp
 
 lemma subset_UNIV: "A \<subseteq> UNIV"
   by (fact top_greatest) (* already simp *)
 
 text \<open>
   \<^medskip>
   Eta-contracting these two rules (to remove \<open>P\<close>) causes them
   to be ignored because of their interaction with congruence rules.
 \<close>
 
 lemma ball_UNIV [simp]: "Ball UNIV P \<longleftrightarrow> All P"
   by (simp add: Ball_def)
 
 lemma bex_UNIV [simp]: "Bex UNIV P \<longleftrightarrow> Ex P"
   by (simp add: Bex_def)
 
 lemma UNIV_eq_I: "(\<And>x. x \<in> A) \<Longrightarrow> UNIV = A"
   by auto
 
 lemma UNIV_not_empty [iff]: "UNIV \<noteq> {}"
   by (blast elim: equalityE)
 
 lemma empty_not_UNIV[simp]: "{} \<noteq> UNIV"
   by blast
 
 
 subsubsection \<open>The Powerset operator -- Pow\<close>
 
 definition Pow :: "'a set \<Rightarrow> 'a set set"
   where Pow_def: "Pow A = {B. B \<subseteq> A}"
 
 lemma Pow_iff [iff]: "A \<in> Pow B \<longleftrightarrow> A \<subseteq> B"
   by (simp add: Pow_def)
 
 lemma PowI: "A \<subseteq> B \<Longrightarrow> A \<in> Pow B"
   by (simp add: Pow_def)
 
 lemma PowD: "A \<in> Pow B \<Longrightarrow> A \<subseteq> B"
   by (simp add: Pow_def)
 
 lemma Pow_bottom: "{} \<in> Pow B"
   by simp
 
 lemma Pow_top: "A \<in> Pow A"
   by simp
 
 lemma Pow_not_empty: "Pow A \<noteq> {}"
   using Pow_top by blast
 
 
 subsubsection \<open>Set complement\<close>
 
 lemma Compl_iff [simp]: "c \<in> - A \<longleftrightarrow> c \<notin> A"
   by (simp add: fun_Compl_def uminus_set_def)
 
 lemma ComplI [intro!]: "(c \<in> A \<Longrightarrow> False) \<Longrightarrow> c \<in> - A"
   by (simp add: fun_Compl_def uminus_set_def) blast
 
 text \<open>
   \<^medskip>
   This form, with negated conclusion, works well with the Classical prover.
   Negated assumptions behave like formulae on the right side of the
   notional turnstile \dots
 \<close>
 
 lemma ComplD [dest!]: "c \<in> - A \<Longrightarrow> c \<notin> A"
   by simp
 
 lemmas ComplE = ComplD [elim_format]
 
 lemma Compl_eq: "- A = {x. \<not> x \<in> A}"
   by blast
 
 
 subsubsection \<open>Binary intersection\<close>
 
 abbreviation inter :: "'a set \<Rightarrow> 'a set \<Rightarrow> 'a set"  (infixl "\<inter>" 70)
   where "(\<inter>) \<equiv> inf"
 
 notation (ASCII)
   inter  (infixl "Int" 70)
 
 lemma Int_def: "A \<inter> B = {x. x \<in> A \<and> x \<in> B}"
   by (simp add: inf_set_def inf_fun_def)
 
 lemma Int_iff [simp]: "c \<in> A \<inter> B \<longleftrightarrow> c \<in> A \<and> c \<in> B"
   unfolding Int_def by blast
 
 lemma IntI [intro!]: "c \<in> A \<Longrightarrow> c \<in> B \<Longrightarrow> c \<in> A \<inter> B"
   by simp
 
 lemma IntD1: "c \<in> A \<inter> B \<Longrightarrow> c \<in> A"
   by simp
 
 lemma IntD2: "c \<in> A \<inter> B \<Longrightarrow> c \<in> B"
   by simp
 
 lemma IntE [elim!]: "c \<in> A \<inter> B \<Longrightarrow> (c \<in> A \<Longrightarrow> c \<in> B \<Longrightarrow> P) \<Longrightarrow> P"
   by simp
 
 lemma mono_Int: "mono f \<Longrightarrow> f (A \<inter> B) \<subseteq> f A \<inter> f B"
   by (fact mono_inf)
 
 
 subsubsection \<open>Binary union\<close>
 
 abbreviation union :: "'a set \<Rightarrow> 'a set \<Rightarrow> 'a set"  (infixl "\<union>" 65)
   where "union \<equiv> sup"
 
 notation (ASCII)
   union  (infixl "Un" 65)
 
 lemma Un_def: "A \<union> B = {x. x \<in> A \<or> x \<in> B}"
   by (simp add: sup_set_def sup_fun_def)
 
 lemma Un_iff [simp]: "c \<in> A \<union> B \<longleftrightarrow> c \<in> A \<or> c \<in> B"
   unfolding Un_def by blast
 
 lemma UnI1 [elim?]: "c \<in> A \<Longrightarrow> c \<in> A \<union> B"
   by simp
 
 lemma UnI2 [elim?]: "c \<in> B \<Longrightarrow> c \<in> A \<union> B"
   by simp
 
 text \<open>\<^medskip> Classical introduction rule: no commitment to \<open>A\<close> vs. \<open>B\<close>.\<close>
 lemma UnCI [intro!]: "(c \<notin> B \<Longrightarrow> c \<in> A) \<Longrightarrow> c \<in> A \<union> B"
   by auto
 
 lemma UnE [elim!]: "c \<in> A \<union> B \<Longrightarrow> (c \<in> A \<Longrightarrow> P) \<Longrightarrow> (c \<in> B \<Longrightarrow> P) \<Longrightarrow> P"
   unfolding Un_def by blast
 
 lemma insert_def: "insert a B = {x. x = a} \<union> B"
   by (simp add: insert_compr Un_def)
 
 lemma mono_Un: "mono f \<Longrightarrow> f A \<union> f B \<subseteq> f (A \<union> B)"
   by (fact mono_sup)
 
 
 subsubsection \<open>Set difference\<close>
 
 lemma Diff_iff [simp]: "c \<in> A - B \<longleftrightarrow> c \<in> A \<and> c \<notin> B"
   by (simp add: minus_set_def fun_diff_def)
 
 lemma DiffI [intro!]: "c \<in> A \<Longrightarrow> c \<notin> B \<Longrightarrow> c \<in> A - B"
   by simp
 
 lemma DiffD1: "c \<in> A - B \<Longrightarrow> c \<in> A"
   by simp
 
 lemma DiffD2: "c \<in> A - B \<Longrightarrow> c \<in> B \<Longrightarrow> P"
   by simp
 
 lemma DiffE [elim!]: "c \<in> A - B \<Longrightarrow> (c \<in> A \<Longrightarrow> c \<notin> B \<Longrightarrow> P) \<Longrightarrow> P"
   by simp
 
 lemma set_diff_eq: "A - B = {x. x \<in> A \<and> x \<notin> B}"
   by blast
 
 lemma Compl_eq_Diff_UNIV: "- A = (UNIV - A)"
   by blast
 
 
 subsubsection \<open>Augmenting a set -- \<^const>\<open>insert\<close>\<close>
 
 lemma insert_iff [simp]: "a \<in> insert b A \<longleftrightarrow> a = b \<or> a \<in> A"
   unfolding insert_def by blast
 
 lemma insertI1: "a \<in> insert a B"
   by simp
 
 lemma insertI2: "a \<in> B \<Longrightarrow> a \<in> insert b B"
   by simp
 
 lemma insertE [elim!]: "a \<in> insert b A \<Longrightarrow> (a = b \<Longrightarrow> P) \<Longrightarrow> (a \<in> A \<Longrightarrow> P) \<Longrightarrow> P"
   unfolding insert_def by blast
 
 lemma insertCI [intro!]: "(a \<notin> B \<Longrightarrow> a = b) \<Longrightarrow> a \<in> insert b B"
   \<comment> \<open>Classical introduction rule.\<close>
   by auto
 
 lemma subset_insert_iff: "A \<subseteq> insert x B \<longleftrightarrow> (if x \<in> A then A - {x} \<subseteq> B else A \<subseteq> B)"
   by auto
 
 lemma set_insert:
   assumes "x \<in> A"
   obtains B where "A = insert x B" and "x \<notin> B"
 proof
   show "A = insert x (A - {x})" using assms by blast
   show "x \<notin> A - {x}" by blast
 qed
 
 lemma insert_ident: "x \<notin> A \<Longrightarrow> x \<notin> B \<Longrightarrow> insert x A = insert x B \<longleftrightarrow> A = B"
   by auto
 
 lemma insert_eq_iff:
   assumes "a \<notin> A" "b \<notin> B"
   shows "insert a A = insert b B \<longleftrightarrow>
     (if a = b then A = B else \<exists>C. A = insert b C \<and> b \<notin> C \<and> B = insert a C \<and> a \<notin> C)"
     (is "?L \<longleftrightarrow> ?R")
 proof
   show ?R if ?L
   proof (cases "a = b")
     case True
     with assms \<open>?L\<close> show ?R
       by (simp add: insert_ident)
   next
     case False
     let ?C = "A - {b}"
     have "A = insert b ?C \<and> b \<notin> ?C \<and> B = insert a ?C \<and> a \<notin> ?C"
       using assms \<open>?L\<close> \<open>a \<noteq> b\<close> by auto
     then show ?R using \<open>a \<noteq> b\<close> by auto
   qed
   show ?L if ?R
     using that by (auto split: if_splits)
 qed
 
 lemma insert_UNIV: "insert x UNIV = UNIV"
   by auto
 
 
 subsubsection \<open>Singletons, using insert\<close>
 
 lemma singletonI [intro!]: "a \<in> {a}"
   \<comment> \<open>Redundant? But unlike \<open>insertCI\<close>, it proves the subgoal immediately!\<close>
   by (rule insertI1)
 
 lemma singletonD [dest!]: "b \<in> {a} \<Longrightarrow> b = a"
   by blast
 
 lemmas singletonE = singletonD [elim_format]
 
 lemma singleton_iff: "b \<in> {a} \<longleftrightarrow> b = a"
   by blast
 
 lemma singleton_inject [dest!]: "{a} = {b} \<Longrightarrow> a = b"
   by blast
 
 lemma singleton_insert_inj_eq [iff]: "{b} = insert a A \<longleftrightarrow> a = b \<and> A \<subseteq> {b}"
   by blast
 
 lemma singleton_insert_inj_eq' [iff]: "insert a A = {b} \<longleftrightarrow> a = b \<and> A \<subseteq> {b}"
   by blast
 
 lemma subset_singletonD: "A \<subseteq> {x} \<Longrightarrow> A = {} \<or> A = {x}"
   by fast
 
 lemma subset_singleton_iff: "X \<subseteq> {a} \<longleftrightarrow> X = {} \<or> X = {a}"
   by blast
 
 lemma subset_singleton_iff_Uniq: "(\<exists>a. A \<subseteq> {a}) \<longleftrightarrow> (\<exists>\<^sub>\<le>\<^sub>1x. x \<in> A)"
   unfolding Uniq_def by blast
 
 lemma singleton_conv [simp]: "{x. x = a} = {a}"
   by blast
 
 lemma singleton_conv2 [simp]: "{x. a = x} = {a}"
   by blast
 
 lemma Diff_single_insert: "A - {x} \<subseteq> B \<Longrightarrow> A \<subseteq> insert x B"
   by blast
 
 lemma subset_Diff_insert: "A \<subseteq> B - insert x C \<longleftrightarrow> A \<subseteq> B - C \<and> x \<notin> A"
   by blast
 
 lemma doubleton_eq_iff: "{a, b} = {c, d} \<longleftrightarrow> a = c \<and> b = d \<or> a = d \<and> b = c"
   by (blast elim: equalityE)
 
 lemma Un_singleton_iff: "A \<union> B = {x} \<longleftrightarrow> A = {} \<and> B = {x} \<or> A = {x} \<and> B = {} \<or> A = {x} \<and> B = {x}"
   by auto
 
 lemma singleton_Un_iff: "{x} = A \<union> B \<longleftrightarrow> A = {} \<and> B = {x} \<or> A = {x} \<and> B = {} \<or> A = {x} \<and> B = {x}"
   by auto
 
 
 subsubsection \<open>Image of a set under a function\<close>
 
 text \<open>Frequently \<open>b\<close> does not have the syntactic form of \<open>f x\<close>.\<close>
 
 definition image :: "('a \<Rightarrow> 'b) \<Rightarrow> 'a set \<Rightarrow> 'b set"    (infixr "`" 90)
   where "f ` A = {y. \<exists>x\<in>A. y = f x}"
 
 lemma image_eqI [simp, intro]: "b = f x \<Longrightarrow> x \<in> A \<Longrightarrow> b \<in> f ` A"
   unfolding image_def by blast
 
 lemma imageI: "x \<in> A \<Longrightarrow> f x \<in> f ` A"
   by (rule image_eqI) (rule refl)
 
 lemma rev_image_eqI: "x \<in> A \<Longrightarrow> b = f x \<Longrightarrow> b \<in> f ` A"
   \<comment> \<open>This version's more effective when we already have the required \<open>x\<close>.\<close>
   by (rule image_eqI)
 
 lemma imageE [elim!]:
   assumes "b \<in> (\<lambda>x. f x) ` A"  \<comment> \<open>The eta-expansion gives variable-name preservation.\<close>
   obtains x where "b = f x" and "x \<in> A"
   using assms unfolding image_def by blast
 
 lemma Compr_image_eq: "{x \<in> f ` A. P x} = f ` {x \<in> A. P (f x)}"
   by auto
 
 lemma image_Un: "f ` (A \<union> B) = f ` A \<union> f ` B"
   by blast
 
 lemma image_iff: "z \<in> f ` A \<longleftrightarrow> (\<exists>x\<in>A. z = f x)"
   by blast
 
 lemma image_subsetI: "(\<And>x. x \<in> A \<Longrightarrow> f x \<in> B) \<Longrightarrow> f ` A \<subseteq> B"
   \<comment> \<open>Replaces the three steps \<open>subsetI\<close>, \<open>imageE\<close>,
     \<open>hypsubst\<close>, but breaks too many existing proofs.\<close>
   by blast
 
 lemma image_subset_iff: "f ` A \<subseteq> B \<longleftrightarrow> (\<forall>x\<in>A. f x \<in> B)"
   \<comment> \<open>This rewrite rule would confuse users if made default.\<close>
   by blast
 
 lemma subset_imageE:
   assumes "B \<subseteq> f ` A"
   obtains C where "C \<subseteq> A" and "B = f ` C"
 proof -
   from assms have "B = f ` {a \<in> A. f a \<in> B}" by fast
   moreover have "{a \<in> A. f a \<in> B} \<subseteq> A" by blast
   ultimately show thesis by (blast intro: that)
 qed
 
 lemma subset_image_iff: "B \<subseteq> f ` A \<longleftrightarrow> (\<exists>AA\<subseteq>A. B = f ` AA)"
   by (blast elim: subset_imageE)
 
 lemma image_ident [simp]: "(\<lambda>x. x) ` Y = Y"
   by blast
 
 lemma image_empty [simp]: "f ` {} = {}"
   by blast
 
 lemma image_insert [simp]: "f ` insert a B = insert (f a) (f ` B)"
   by blast
 
 lemma image_constant: "x \<in> A \<Longrightarrow> (\<lambda>x. c) ` A = {c}"
   by auto
 
 lemma image_constant_conv: "(\<lambda>x. c) ` A = (if A = {} then {} else {c})"
   by auto
 
 lemma image_image: "f ` (g ` A) = (\<lambda>x. f (g x)) ` A"
   by blast
 
 lemma insert_image [simp]: "x \<in> A \<Longrightarrow> insert (f x) (f ` A) = f ` A"
   by blast
 
 lemma image_is_empty [iff]: "f ` A = {} \<longleftrightarrow> A = {}"
   by blast
 
 lemma empty_is_image [iff]: "{} = f ` A \<longleftrightarrow> A = {}"
   by blast
 
 lemma image_Collect: "f ` {x. P x} = {f x | x. P x}"
   \<comment> \<open>NOT suitable as a default simp rule: the RHS isn't simpler than the LHS,
       with its implicit quantifier and conjunction.  Also image enjoys better
       equational properties than does the RHS.\<close>
   by blast
 
 lemma if_image_distrib [simp]:
   "(\<lambda>x. if P x then f x else g x) ` S = f ` (S \<inter> {x. P x}) \<union> g ` (S \<inter> {x. \<not> P x})"
   by auto
 
 lemma image_cong:
   "f ` M = g ` N" if "M = N" "\<And>x. x \<in> N \<Longrightarrow> f x = g x"
   using that by (simp add: image_def)
 
 lemma image_cong_simp [cong]:
   "f ` M = g ` N" if "M = N" "\<And>x. x \<in> N =simp=> f x = g x"
   using that image_cong [of M N f g] by (simp add: simp_implies_def)
 
 lemma image_Int_subset: "f ` (A \<inter> B) \<subseteq> f ` A \<inter> f ` B"
   by blast
 
 lemma image_diff_subset: "f ` A - f ` B \<subseteq> f ` (A - B)"
   by blast
 
 lemma Setcompr_eq_image: "{f x |x. x \<in> A} = f ` A"
   by blast
 
 lemma setcompr_eq_image: "{f x |x. P x} = f ` {x. P x}"
   by auto
 
 lemma ball_imageD: "\<forall>x\<in>f ` A. P x \<Longrightarrow> \<forall>x\<in>A. P (f x)"
   by simp
 
 lemma bex_imageD: "\<exists>x\<in>f ` A. P x \<Longrightarrow> \<exists>x\<in>A. P (f x)"
   by auto
 
 lemma image_add_0 [simp]: "(+) (0::'a::comm_monoid_add) ` S = S"
   by auto
 
 
 text \<open>\<^medskip> Range of a function -- just an abbreviation for image!\<close>
 
 abbreviation range :: "('a \<Rightarrow> 'b) \<Rightarrow> 'b set"  \<comment> \<open>of function\<close>
   where "range f \<equiv> f ` UNIV"
 
 lemma range_eqI: "b = f x \<Longrightarrow> b \<in> range f"
   by simp
 
 lemma rangeI: "f x \<in> range f"
   by simp
 
 lemma rangeE [elim?]: "b \<in> range (\<lambda>x. f x) \<Longrightarrow> (\<And>x. b = f x \<Longrightarrow> P) \<Longrightarrow> P"
   by (rule imageE)
 
 lemma full_SetCompr_eq: "{u. \<exists>x. u = f x} = range f"
   by auto
 
 lemma range_composition: "range (\<lambda>x. f (g x)) = f ` range g"
   by auto
 
 lemma range_constant [simp]: "range (\<lambda>_. x) = {x}"
   by (simp add: image_constant)
 
 lemma range_eq_singletonD: "range f = {a} \<Longrightarrow> f x = a"
   by auto
 
 
 subsubsection \<open>Some rules with \<open>if\<close>\<close>
 
 text \<open>Elimination of \<open>{x. \<dots> \<and> x = t \<and> \<dots>}\<close>.\<close>
 
 lemma Collect_conv_if: "{x. x = a \<and> P x} = (if P a then {a} else {})"
   by auto
 
 lemma Collect_conv_if2: "{x. a = x \<and> P x} = (if P a then {a} else {})"
   by auto
 
 text \<open>
   Rewrite rules for boolean case-splitting: faster than \<open>if_split [split]\<close>.
 \<close>
 
 lemma if_split_eq1: "(if Q then x else y) = b \<longleftrightarrow> (Q \<longrightarrow> x = b) \<and> (\<not> Q \<longrightarrow> y = b)"
   by (rule if_split)
 
 lemma if_split_eq2: "a = (if Q then x else y) \<longleftrightarrow> (Q \<longrightarrow> a = x) \<and> (\<not> Q \<longrightarrow> a = y)"
   by (rule if_split)
 
 text \<open>
   Split ifs on either side of the membership relation.
   Not for \<open>[simp]\<close> -- can cause goals to blow up!
 \<close>
 
 lemma if_split_mem1: "(if Q then x else y) \<in> b \<longleftrightarrow> (Q \<longrightarrow> x \<in> b) \<and> (\<not> Q \<longrightarrow> y \<in> b)"
   by (rule if_split)
 
 lemma if_split_mem2: "(a \<in> (if Q then x else y)) \<longleftrightarrow> (Q \<longrightarrow> a \<in> x) \<and> (\<not> Q \<longrightarrow> a \<in> y)"
   by (rule if_split [where P = "\<lambda>S. a \<in> S"])
 
 lemmas split_ifs = if_bool_eq_conj if_split_eq1 if_split_eq2 if_split_mem1 if_split_mem2
 
 (*Would like to add these, but the existing code only searches for the
   outer-level constant, which in this case is just Set.member; we instead need
   to use term-nets to associate patterns with rules.  Also, if a rule fails to
   apply, then the formula should be kept.
   [("uminus", Compl_iff RS iffD1), ("minus", [Diff_iff RS iffD1]),
    ("Int", [IntD1,IntD2]),
    ("Collect", [CollectD]), ("Inter", [InterD]), ("INTER", [INT_D])]
  *)
 
 
 subsection \<open>Further operations and lemmas\<close>
 
 subsubsection \<open>The ``proper subset'' relation\<close>
 
 lemma psubsetI [intro!]: "A \<subseteq> B \<Longrightarrow> A \<noteq> B \<Longrightarrow> A \<subset> B"
   unfolding less_le by blast
 
 lemma psubsetE [elim!]: "A \<subset> B \<Longrightarrow> (A \<subseteq> B \<Longrightarrow> \<not> B \<subseteq> A \<Longrightarrow> R) \<Longrightarrow> R"
   unfolding less_le by blast
 
 lemma psubset_insert_iff:
   "A \<subset> insert x B \<longleftrightarrow> (if x \<in> B then A \<subset> B else if x \<in> A then A - {x} \<subset> B else A \<subseteq> B)"
   by (auto simp add: less_le subset_insert_iff)
 
 lemma psubset_eq: "A \<subset> B \<longleftrightarrow> A \<subseteq> B \<and> A \<noteq> B"
   by (simp only: less_le)
 
 lemma psubset_imp_subset: "A \<subset> B \<Longrightarrow> A \<subseteq> B"
   by (simp add: psubset_eq)
 
 lemma psubset_trans: "A \<subset> B \<Longrightarrow> B \<subset> C \<Longrightarrow> A \<subset> C"
   unfolding less_le by (auto dest: subset_antisym)
 
 lemma psubsetD: "A \<subset> B \<Longrightarrow> c \<in> A \<Longrightarrow> c \<in> B"
   unfolding less_le by (auto dest: subsetD)
 
 lemma psubset_subset_trans: "A \<subset> B \<Longrightarrow> B \<subseteq> C \<Longrightarrow> A \<subset> C"
   by (auto simp add: psubset_eq)
 
 lemma subset_psubset_trans: "A \<subseteq> B \<Longrightarrow> B \<subset> C \<Longrightarrow> A \<subset> C"
   by (auto simp add: psubset_eq)
 
 lemma psubset_imp_ex_mem: "A \<subset> B \<Longrightarrow> \<exists>b. b \<in> B - A"
   unfolding less_le by blast
 
 lemma atomize_ball: "(\<And>x. x \<in> A \<Longrightarrow> P x) \<equiv> Trueprop (\<forall>x\<in>A. P x)"
   by (simp only: Ball_def atomize_all atomize_imp)
 
 lemmas [symmetric, rulify] = atomize_ball
   and [symmetric, defn] = atomize_ball
 
 lemma image_Pow_mono: "f ` A \<subseteq> B \<Longrightarrow> image f ` Pow A \<subseteq> Pow B"
   by blast
 
 lemma image_Pow_surj: "f ` A = B \<Longrightarrow> image f ` Pow A = Pow B"
   by (blast elim: subset_imageE)
 
 
 subsubsection \<open>Derived rules involving subsets.\<close>
 
 text \<open>\<open>insert\<close>.\<close>
 
 lemma subset_insertI: "B \<subseteq> insert a B"
   by (rule subsetI) (erule insertI2)
 
 lemma subset_insertI2: "A \<subseteq> B \<Longrightarrow> A \<subseteq> insert b B"
   by blast
 
 lemma subset_insert: "x \<notin> A \<Longrightarrow> A \<subseteq> insert x B \<longleftrightarrow> A \<subseteq> B"
   by blast
 
 
 text \<open>\<^medskip> Finite Union -- the least upper bound of two sets.\<close>
 
 lemma Un_upper1: "A \<subseteq> A \<union> B"
   by (fact sup_ge1)
 
 lemma Un_upper2: "B \<subseteq> A \<union> B"
   by (fact sup_ge2)
 
 lemma Un_least: "A \<subseteq> C \<Longrightarrow> B \<subseteq> C \<Longrightarrow> A \<union> B \<subseteq> C"
   by (fact sup_least)
 
 
 text \<open>\<^medskip> Finite Intersection -- the greatest lower bound of two sets.\<close>
 
 lemma Int_lower1: "A \<inter> B \<subseteq> A"
   by (fact inf_le1)
 
 lemma Int_lower2: "A \<inter> B \<subseteq> B"
   by (fact inf_le2)
 
 lemma Int_greatest: "C \<subseteq> A \<Longrightarrow> C \<subseteq> B \<Longrightarrow> C \<subseteq> A \<inter> B"
   by (fact inf_greatest)
 
 
 text \<open>\<^medskip> Set difference.\<close>
 
 lemma Diff_subset[simp]: "A - B \<subseteq> A"
   by blast
 
 lemma Diff_subset_conv: "A - B \<subseteq> C \<longleftrightarrow> A \<subseteq> B \<union> C"
   by blast
 
 
 subsubsection \<open>Equalities involving union, intersection, inclusion, etc.\<close>
 
 text \<open>\<open>{}\<close>.\<close>
 
 lemma Collect_const [simp]: "{s. P} = (if P then UNIV else {})"
   \<comment> \<open>supersedes \<open>Collect_False_empty\<close>\<close>
   by auto
 
 lemma subset_empty [simp]: "A \<subseteq> {} \<longleftrightarrow> A = {}"
   by (fact bot_unique)
 
 lemma not_psubset_empty [iff]: "\<not> (A < {})"
   by (fact not_less_bot) (* FIXME: already simp *)
 
 lemma Collect_subset [simp]: "{x\<in>A. P x} \<subseteq> A" by auto
 
 lemma Collect_empty_eq [simp]: "Collect P = {} \<longleftrightarrow> (\<forall>x. \<not> P x)"
   by blast
 
 lemma empty_Collect_eq [simp]: "{} = Collect P \<longleftrightarrow> (\<forall>x. \<not> P x)"
   by blast
 
 lemma Collect_neg_eq: "{x. \<not> P x} = - {x. P x}"
   by blast
 
 lemma Collect_disj_eq: "{x. P x \<or> Q x} = {x. P x} \<union> {x. Q x}"
   by blast
 
 lemma Collect_imp_eq: "{x. P x \<longrightarrow> Q x} = - {x. P x} \<union> {x. Q x}"
   by blast
 
 lemma Collect_conj_eq: "{x. P x \<and> Q x} = {x. P x} \<inter> {x. Q x}"
   by blast
 
 lemma Collect_mono_iff: "Collect P \<subseteq> Collect Q \<longleftrightarrow> (\<forall>x. P x \<longrightarrow> Q x)"
   by blast
 
 
 text \<open>\<^medskip> \<open>insert\<close>.\<close>
 
 lemma insert_is_Un: "insert a A = {a} \<union> A"
   \<comment> \<open>NOT SUITABLE FOR REWRITING since \<open>{a} \<equiv> insert a {}\<close>\<close>
   by blast
 
 lemma insert_not_empty [simp]: "insert a A \<noteq> {}"
   and empty_not_insert [simp]: "{} \<noteq> insert a A"
   by blast+
 
 lemma insert_absorb: "a \<in> A \<Longrightarrow> insert a A = A"
   \<comment> \<open>\<open>[simp]\<close> causes recursive calls when there are nested inserts\<close>
   \<comment> \<open>with \<^emph>\<open>quadratic\<close> running time\<close>
   by blast
 
 lemma insert_absorb2 [simp]: "insert x (insert x A) = insert x A"
   by blast
 
 lemma insert_commute: "insert x (insert y A) = insert y (insert x A)"
   by blast
 
 lemma insert_subset [simp]: "insert x A \<subseteq> B \<longleftrightarrow> x \<in> B \<and> A \<subseteq> B"
   by blast
 
 lemma mk_disjoint_insert: "a \<in> A \<Longrightarrow> \<exists>B. A = insert a B \<and> a \<notin> B"
   \<comment> \<open>use new \<open>B\<close> rather than \<open>A - {a}\<close> to avoid infinite unfolding\<close>
   by (rule exI [where x = "A - {a}"]) blast
 
 lemma insert_Collect: "insert a (Collect P) = {u. u \<noteq> a \<longrightarrow> P u}"
   by auto
 
 lemma insert_inter_insert [simp]: "insert a A \<inter> insert a B = insert a (A \<inter> B)"
   by blast
 
 lemma insert_disjoint [simp]:
   "insert a A \<inter> B = {} \<longleftrightarrow> a \<notin> B \<and> A \<inter> B = {}"
   "{} = insert a A \<inter> B \<longleftrightarrow> a \<notin> B \<and> {} = A \<inter> B"
   by auto
 
 lemma disjoint_insert [simp]:
   "B \<inter> insert a A = {} \<longleftrightarrow> a \<notin> B \<and> B \<inter> A = {}"
   "{} = A \<inter> insert b B \<longleftrightarrow> b \<notin> A \<and> {} = A \<inter> B"
   by auto
 
 
 text \<open>\<^medskip> \<open>Int\<close>\<close>
 
 lemma Int_absorb: "A \<inter> A = A"
   by (fact inf_idem) (* already simp *)
 
 lemma Int_left_absorb: "A \<inter> (A \<inter> B) = A \<inter> B"
   by (fact inf_left_idem)
 
 lemma Int_commute: "A \<inter> B = B \<inter> A"
   by (fact inf_commute)
 
 lemma Int_left_commute: "A \<inter> (B \<inter> C) = B \<inter> (A \<inter> C)"
   by (fact inf_left_commute)
 
 lemma Int_assoc: "(A \<inter> B) \<inter> C = A \<inter> (B \<inter> C)"
   by (fact inf_assoc)
 
 lemmas Int_ac = Int_assoc Int_left_absorb Int_commute Int_left_commute
   \<comment> \<open>Intersection is an AC-operator\<close>
 
 lemma Int_absorb1: "B \<subseteq> A \<Longrightarrow> A \<inter> B = B"
   by (fact inf_absorb2)
 
 lemma Int_absorb2: "A \<subseteq> B \<Longrightarrow> A \<inter> B = A"
   by (fact inf_absorb1)
 
 lemma Int_empty_left: "{} \<inter> B = {}"
   by (fact inf_bot_left) (* already simp *)
 
 lemma Int_empty_right: "A \<inter> {} = {}"
   by (fact inf_bot_right) (* already simp *)
 
 lemma disjoint_eq_subset_Compl: "A \<inter> B = {} \<longleftrightarrow> A \<subseteq> - B"
   by blast
 
 lemma disjoint_iff: "A \<inter> B = {} \<longleftrightarrow> (\<forall>x. x\<in>A \<longrightarrow> x \<notin> B)"
   by blast
 
 lemma disjoint_iff_not_equal: "A \<inter> B = {} \<longleftrightarrow> (\<forall>x\<in>A. \<forall>y\<in>B. x \<noteq> y)"
   by blast
 
 lemma Int_UNIV_left: "UNIV \<inter> B = B"
   by (fact inf_top_left) (* already simp *)
 
 lemma Int_UNIV_right: "A \<inter> UNIV = A"
   by (fact inf_top_right) (* already simp *)
 
 lemma Int_Un_distrib: "A \<inter> (B \<union> C) = (A \<inter> B) \<union> (A \<inter> C)"
   by (fact inf_sup_distrib1)
 
 lemma Int_Un_distrib2: "(B \<union> C) \<inter> A = (B \<inter> A) \<union> (C \<inter> A)"
   by (fact inf_sup_distrib2)
 
 lemma Int_UNIV [simp]: "A \<inter> B = UNIV \<longleftrightarrow> A = UNIV \<and> B = UNIV"
   by (fact inf_eq_top_iff) (* already simp *)
 
 lemma Int_subset_iff [simp]: "C \<subseteq> A \<inter> B \<longleftrightarrow> C \<subseteq> A \<and> C \<subseteq> B"
   by (fact le_inf_iff)
 
 lemma Int_Collect: "x \<in> A \<inter> {x. P x} \<longleftrightarrow> x \<in> A \<and> P x"
   by blast
 
 
 text \<open>\<^medskip> \<open>Un\<close>.\<close>
 
 lemma Un_absorb: "A \<union> A = A"
   by (fact sup_idem) (* already simp *)
 
 lemma Un_left_absorb: "A \<union> (A \<union> B) = A \<union> B"
   by (fact sup_left_idem)
 
 lemma Un_commute: "A \<union> B = B \<union> A"
   by (fact sup_commute)
 
 lemma Un_left_commute: "A \<union> (B \<union> C) = B \<union> (A \<union> C)"
   by (fact sup_left_commute)
 
 lemma Un_assoc: "(A \<union> B) \<union> C = A \<union> (B \<union> C)"
   by (fact sup_assoc)
 
 lemmas Un_ac = Un_assoc Un_left_absorb Un_commute Un_left_commute
   \<comment> \<open>Union is an AC-operator\<close>
 
 lemma Un_absorb1: "A \<subseteq> B \<Longrightarrow> A \<union> B = B"
   by (fact sup_absorb2)
 
 lemma Un_absorb2: "B \<subseteq> A \<Longrightarrow> A \<union> B = A"
   by (fact sup_absorb1)
 
 lemma Un_empty_left: "{} \<union> B = B"
   by (fact sup_bot_left) (* already simp *)
 
 lemma Un_empty_right: "A \<union> {} = A"
   by (fact sup_bot_right) (* already simp *)
 
 lemma Un_UNIV_left: "UNIV \<union> B = UNIV"
   by (fact sup_top_left) (* already simp *)
 
 lemma Un_UNIV_right: "A \<union> UNIV = UNIV"
   by (fact sup_top_right) (* already simp *)
 
 lemma Un_insert_left [simp]: "(insert a B) \<union> C = insert a (B \<union> C)"
   by blast
 
 lemma Un_insert_right [simp]: "A \<union> (insert a B) = insert a (A \<union> B)"
   by blast
 
 lemma Int_insert_left: "(insert a B) \<inter> C = (if a \<in> C then insert a (B \<inter> C) else B \<inter> C)"
   by auto
 
 lemma Int_insert_left_if0 [simp]: "a \<notin> C \<Longrightarrow> (insert a B) \<inter> C = B \<inter> C"
   by auto
 
 lemma Int_insert_left_if1 [simp]: "a \<in> C \<Longrightarrow> (insert a B) \<inter> C = insert a (B \<inter> C)"
   by auto
 
 lemma Int_insert_right: "A \<inter> (insert a B) = (if a \<in> A then insert a (A \<inter> B) else A \<inter> B)"
   by auto
 
 lemma Int_insert_right_if0 [simp]: "a \<notin> A \<Longrightarrow> A \<inter> (insert a B) = A \<inter> B"
   by auto
 
 lemma Int_insert_right_if1 [simp]: "a \<in> A \<Longrightarrow> A \<inter> (insert a B) = insert a (A \<inter> B)"
   by auto
 
 lemma Un_Int_distrib: "A \<union> (B \<inter> C) = (A \<union> B) \<inter> (A \<union> C)"
   by (fact sup_inf_distrib1)
 
 lemma Un_Int_distrib2: "(B \<inter> C) \<union> A = (B \<union> A) \<inter> (C \<union> A)"
   by (fact sup_inf_distrib2)
 
 lemma Un_Int_crazy: "(A \<inter> B) \<union> (B \<inter> C) \<union> (C \<inter> A) = (A \<union> B) \<inter> (B \<union> C) \<inter> (C \<union> A)"
   by blast
 
 lemma subset_Un_eq: "A \<subseteq> B \<longleftrightarrow> A \<union> B = B"
   by (fact le_iff_sup)
 
 lemma Un_empty [iff]: "A \<union> B = {} \<longleftrightarrow> A = {} \<and> B = {}"
   by (fact sup_eq_bot_iff) (* FIXME: already simp *)
 
 lemma Un_subset_iff [simp]: "A \<union> B \<subseteq> C \<longleftrightarrow> A \<subseteq> C \<and> B \<subseteq> C"
   by (fact le_sup_iff)
 
 lemma Un_Diff_Int: "(A - B) \<union> (A \<inter> B) = A"
   by blast
 
 lemma Diff_Int2: "A \<inter> C - B \<inter> C = A \<inter> C - B"
   by blast
 
 lemma subset_UnE: 
   assumes "C \<subseteq> A \<union> B"
   obtains A' B' where "A' \<subseteq> A" "B' \<subseteq> B" "C = A' \<union> B'"
 proof
   show "C \<inter> A \<subseteq> A" "C \<inter> B \<subseteq> B" "C = (C \<inter> A) \<union> (C \<inter> B)"
     using assms by blast+
 qed
 
 lemma Un_Int_eq [simp]: "(S \<union> T) \<inter> S = S" "(S \<union> T) \<inter> T = T" "S \<inter> (S \<union> T) = S" "T \<inter> (S \<union> T) = T"
   by auto
 
 lemma Int_Un_eq [simp]: "(S \<inter> T) \<union> S = S" "(S \<inter> T) \<union> T = T" "S \<union> (S \<inter> T) = S" "T \<union> (S \<inter> T) = T"
   by auto
 
 text \<open>\<^medskip> Set complement\<close>
 
 lemma Compl_disjoint [simp]: "A \<inter> - A = {}"
   by (fact inf_compl_bot)
 
 lemma Compl_disjoint2 [simp]: "- A \<inter> A = {}"
   by (fact compl_inf_bot)
 
 lemma Compl_partition: "A \<union> - A = UNIV"
   by (fact sup_compl_top)
 
 lemma Compl_partition2: "- A \<union> A = UNIV"
   by (fact compl_sup_top)
 
 lemma double_complement: "- (-A) = A" for A :: "'a set"
   by (fact double_compl) (* already simp *)
 
 lemma Compl_Un: "- (A \<union> B) = (- A) \<inter> (- B)"
   by (fact compl_sup) (* already simp *)
 
 lemma Compl_Int: "- (A \<inter> B) = (- A) \<union> (- B)"
   by (fact compl_inf) (* already simp *)
 
 lemma subset_Compl_self_eq: "A \<subseteq> - A \<longleftrightarrow> A = {}"
   by blast
 
 lemma Un_Int_assoc_eq: "(A \<inter> B) \<union> C = A \<inter> (B \<union> C) \<longleftrightarrow> C \<subseteq> A"
   \<comment> \<open>Halmos, Naive Set Theory, page 16.\<close>
   by blast
 
 lemma Compl_UNIV_eq: "- UNIV = {}"
   by (fact compl_top_eq) (* already simp *)
 
 lemma Compl_empty_eq: "- {} = UNIV"
   by (fact compl_bot_eq) (* already simp *)
 
 lemma Compl_subset_Compl_iff [iff]: "- A \<subseteq> - B \<longleftrightarrow> B \<subseteq> A"
   by (fact compl_le_compl_iff) (* FIXME: already simp *)
 
 lemma Compl_eq_Compl_iff [iff]: "- A = - B \<longleftrightarrow> A = B"
   for A B :: "'a set"
   by (fact compl_eq_compl_iff) (* FIXME: already simp *)
 
 lemma Compl_insert: "- insert x A = (- A) - {x}"
   by blast
 
 text \<open>\<^medskip> Bounded quantifiers.
 
   The following are not added to the default simpset because
   (a) they duplicate the body and (b) there are no similar rules for \<open>Int\<close>.
 \<close>
 
 lemma ball_Un: "(\<forall>x \<in> A \<union> B. P x) \<longleftrightarrow> (\<forall>x\<in>A. P x) \<and> (\<forall>x\<in>B. P x)"
   by blast
 
 lemma bex_Un: "(\<exists>x \<in> A \<union> B. P x) \<longleftrightarrow> (\<exists>x\<in>A. P x) \<or> (\<exists>x\<in>B. P x)"
   by blast
 
 
 text \<open>\<^medskip> Set difference.\<close>
 
 lemma Diff_eq: "A - B = A \<inter> (- B)"
   by blast
 
 lemma Diff_eq_empty_iff [simp]: "A - B = {} \<longleftrightarrow> A \<subseteq> B"
   by blast
 
 lemma Diff_cancel [simp]: "A - A = {}"
   by blast
 
 lemma Diff_idemp [simp]: "(A - B) - B = A - B"
   for A B :: "'a set"
   by blast
 
 lemma Diff_triv: "A \<inter> B = {} \<Longrightarrow> A - B = A"
   by (blast elim: equalityE)
 
 lemma empty_Diff [simp]: "{} - A = {}"
   by blast
 
 lemma Diff_empty [simp]: "A - {} = A"
   by blast
 
 lemma Diff_UNIV [simp]: "A - UNIV = {}"
   by blast
 
 lemma Diff_insert0 [simp]: "x \<notin> A \<Longrightarrow> A - insert x B = A - B"
   by blast
 
 lemma Diff_insert: "A - insert a B = A - B - {a}"
   \<comment> \<open>NOT SUITABLE FOR REWRITING since \<open>{a} \<equiv> insert a 0\<close>\<close>
   by blast
 
 lemma Diff_insert2: "A - insert a B = A - {a} - B"
   \<comment> \<open>NOT SUITABLE FOR REWRITING since \<open>{a} \<equiv> insert a 0\<close>\<close>
   by blast
 
 lemma insert_Diff_if: "insert x A - B = (if x \<in> B then A - B else insert x (A - B))"
   by auto
 
 lemma insert_Diff1 [simp]: "x \<in> B \<Longrightarrow> insert x A - B = A - B"
   by blast
 
 lemma insert_Diff_single[simp]: "insert a (A - {a}) = insert a A"
   by blast
 
 lemma insert_Diff: "a \<in> A \<Longrightarrow> insert a (A - {a}) = A"
   by blast
 
 lemma Diff_insert_absorb: "x \<notin> A \<Longrightarrow> (insert x A) - {x} = A"
   by auto
 
 lemma Diff_disjoint [simp]: "A \<inter> (B - A) = {}"
   by blast
 
 lemma Diff_partition: "A \<subseteq> B \<Longrightarrow> A \<union> (B - A) = B"
   by blast
 
 lemma double_diff: "A \<subseteq> B \<Longrightarrow> B \<subseteq> C \<Longrightarrow> B - (C - A) = A"
   by blast
 
 lemma Un_Diff_cancel [simp]: "A \<union> (B - A) = A \<union> B"
   by blast
 
 lemma Un_Diff_cancel2 [simp]: "(B - A) \<union> A = B \<union> A"
   by blast
 
 lemma Diff_Un: "A - (B \<union> C) = (A - B) \<inter> (A - C)"
   by blast
 
 lemma Diff_Int: "A - (B \<inter> C) = (A - B) \<union> (A - C)"
   by blast
 
 lemma Diff_Diff_Int: "A - (A - B) = A \<inter> B"
   by blast
 
 lemma Un_Diff: "(A \<union> B) - C = (A - C) \<union> (B - C)"
   by blast
 
 lemma Int_Diff: "(A \<inter> B) - C = A \<inter> (B - C)"
   by blast
 
 lemma Diff_Int_distrib: "C \<inter> (A - B) = (C \<inter> A) - (C \<inter> B)"
   by blast
 
 lemma Diff_Int_distrib2: "(A - B) \<inter> C = (A \<inter> C) - (B \<inter> C)"
   by blast
 
 lemma Diff_Compl [simp]: "A - (- B) = A \<inter> B"
   by auto
 
 lemma Compl_Diff_eq [simp]: "- (A - B) = - A \<union> B"
   by blast
 
 lemma subset_Compl_singleton [simp]: "A \<subseteq> - {b} \<longleftrightarrow> b \<notin> A"
   by blast
 
 text \<open>\<^medskip> Quantification over type \<^typ>\<open>bool\<close>.\<close>
 
 lemma bool_induct: "P True \<Longrightarrow> P False \<Longrightarrow> P x"
   by (cases x) auto
 
 lemma all_bool_eq: "(\<forall>b. P b) \<longleftrightarrow> P True \<and> P False"
   by (auto intro: bool_induct)
 
 lemma bool_contrapos: "P x \<Longrightarrow> \<not> P False \<Longrightarrow> P True"
   by (cases x) auto
 
 lemma ex_bool_eq: "(\<exists>b. P b) \<longleftrightarrow> P True \<or> P False"
   by (auto intro: bool_contrapos)
 
 lemma UNIV_bool: "UNIV = {False, True}"
   by (auto intro: bool_induct)
 
 text \<open>\<^medskip> \<open>Pow\<close>\<close>
 
 lemma Pow_empty [simp]: "Pow {} = {{}}"
   by (auto simp add: Pow_def)
 
 lemma Pow_singleton_iff [simp]: "Pow X = {Y} \<longleftrightarrow> X = {} \<and> Y = {}"
   by blast  (* somewhat slow *)
 
 lemma Pow_insert: "Pow (insert a A) = Pow A \<union> (insert a ` Pow A)"
   by (blast intro: image_eqI [where ?x = "u - {a}" for u])
 
 lemma Pow_Compl: "Pow (- A) = {- B | B. A \<in> Pow B}"
   by (blast intro: exI [where ?x = "- u" for u])
 
 lemma Pow_UNIV [simp]: "Pow UNIV = UNIV"
   by blast
 
 lemma Un_Pow_subset: "Pow A \<union> Pow B \<subseteq> Pow (A \<union> B)"
   by blast
 
 lemma Pow_Int_eq [simp]: "Pow (A \<inter> B) = Pow A \<inter> Pow B"
   by blast
 
 
 text \<open>\<^medskip> Miscellany.\<close>
 
 lemma set_eq_subset: "A = B \<longleftrightarrow> A \<subseteq> B \<and> B \<subseteq> A"
   by blast
 
 lemma subset_iff: "A \<subseteq> B \<longleftrightarrow> (\<forall>t. t \<in> A \<longrightarrow> t \<in> B)"
   by blast
 
 lemma subset_iff_psubset_eq: "A \<subseteq> B \<longleftrightarrow> A \<subset> B \<or> A = B"
   unfolding less_le by blast
 
 lemma all_not_in_conv [simp]: "(\<forall>x. x \<notin> A) \<longleftrightarrow> A = {}"
   by blast
 
 lemma ex_in_conv: "(\<exists>x. x \<in> A) \<longleftrightarrow> A \<noteq> {}"
   by blast
 
 lemma ball_simps [simp, no_atp]:
   "\<And>A P Q. (\<forall>x\<in>A. P x \<or> Q) \<longleftrightarrow> ((\<forall>x\<in>A. P x) \<or> Q)"
   "\<And>A P Q. (\<forall>x\<in>A. P \<or> Q x) \<longleftrightarrow> (P \<or> (\<forall>x\<in>A. Q x))"
   "\<And>A P Q. (\<forall>x\<in>A. P \<longrightarrow> Q x) \<longleftrightarrow> (P \<longrightarrow> (\<forall>x\<in>A. Q x))"
   "\<And>A P Q. (\<forall>x\<in>A. P x \<longrightarrow> Q) \<longleftrightarrow> ((\<exists>x\<in>A. P x) \<longrightarrow> Q)"
   "\<And>P. (\<forall>x\<in>{}. P x) \<longleftrightarrow> True"
   "\<And>P. (\<forall>x\<in>UNIV. P x) \<longleftrightarrow> (\<forall>x. P x)"
   "\<And>a B P. (\<forall>x\<in>insert a B. P x) \<longleftrightarrow> (P a \<and> (\<forall>x\<in>B. P x))"
   "\<And>P Q. (\<forall>x\<in>Collect Q. P x) \<longleftrightarrow> (\<forall>x. Q x \<longrightarrow> P x)"
   "\<And>A P f. (\<forall>x\<in>f`A. P x) \<longleftrightarrow> (\<forall>x\<in>A. P (f x))"
   "\<And>A P. (\<not> (\<forall>x\<in>A. P x)) \<longleftrightarrow> (\<exists>x\<in>A. \<not> P x)"
   by auto
 
 lemma bex_simps [simp, no_atp]:
   "\<And>A P Q. (\<exists>x\<in>A. P x \<and> Q) \<longleftrightarrow> ((\<exists>x\<in>A. P x) \<and> Q)"
   "\<And>A P Q. (\<exists>x\<in>A. P \<and> Q x) \<longleftrightarrow> (P \<and> (\<exists>x\<in>A. Q x))"
   "\<And>P. (\<exists>x\<in>{}. P x) \<longleftrightarrow> False"
   "\<And>P. (\<exists>x\<in>UNIV. P x) \<longleftrightarrow> (\<exists>x. P x)"
   "\<And>a B P. (\<exists>x\<in>insert a B. P x) \<longleftrightarrow> (P a \<or> (\<exists>x\<in>B. P x))"
   "\<And>P Q. (\<exists>x\<in>Collect Q. P x) \<longleftrightarrow> (\<exists>x. Q x \<and> P x)"
   "\<And>A P f. (\<exists>x\<in>f`A. P x) \<longleftrightarrow> (\<exists>x\<in>A. P (f x))"
   "\<And>A P. (\<not>(\<exists>x\<in>A. P x)) \<longleftrightarrow> (\<forall>x\<in>A. \<not> P x)"
   by auto
 
 lemma ex_image_cong_iff [simp, no_atp]:
   "(\<exists>x. x\<in>f`A) \<longleftrightarrow> A \<noteq> {}" "(\<exists>x. x\<in>f`A \<and> P x) \<longleftrightarrow> (\<exists>x\<in>A. P (f x))"
   by auto
 
 subsubsection \<open>Monotonicity of various operations\<close>
 
 lemma image_mono: "A \<subseteq> B \<Longrightarrow> f ` A \<subseteq> f ` B"
   by blast
 
 lemma Pow_mono: "A \<subseteq> B \<Longrightarrow> Pow A \<subseteq> Pow B"
   by blast
 
 lemma insert_mono: "C \<subseteq> D \<Longrightarrow> insert a C \<subseteq> insert a D"
   by blast
 
 lemma Un_mono: "A \<subseteq> C \<Longrightarrow> B \<subseteq> D \<Longrightarrow> A \<union> B \<subseteq> C \<union> D"
   by (fact sup_mono)
 
 lemma Int_mono: "A \<subseteq> C \<Longrightarrow> B \<subseteq> D \<Longrightarrow> A \<inter> B \<subseteq> C \<inter> D"
   by (fact inf_mono)
 
 lemma Diff_mono: "A \<subseteq> C \<Longrightarrow> D \<subseteq> B \<Longrightarrow> A - B \<subseteq> C - D"
   by blast
 
 lemma Compl_anti_mono: "A \<subseteq> B \<Longrightarrow> - B \<subseteq> - A"
   by (fact compl_mono)
 
 text \<open>\<^medskip> Monotonicity of implications.\<close>
 
 lemma in_mono: "A \<subseteq> B \<Longrightarrow> x \<in> A \<longrightarrow> x \<in> B"
   by (rule impI) (erule subsetD)
 
 lemma conj_mono: "P1 \<longrightarrow> Q1 \<Longrightarrow> P2 \<longrightarrow> Q2 \<Longrightarrow> (P1 \<and> P2) \<longrightarrow> (Q1 \<and> Q2)"
   by iprover
 
 lemma disj_mono: "P1 \<longrightarrow> Q1 \<Longrightarrow> P2 \<longrightarrow> Q2 \<Longrightarrow> (P1 \<or> P2) \<longrightarrow> (Q1 \<or> Q2)"
   by iprover
 
 lemma imp_mono: "Q1 \<longrightarrow> P1 \<Longrightarrow> P2 \<longrightarrow> Q2 \<Longrightarrow> (P1 \<longrightarrow> P2) \<longrightarrow> (Q1 \<longrightarrow> Q2)"
   by iprover
 
 lemma imp_refl: "P \<longrightarrow> P" ..
 
 lemma not_mono: "Q \<longrightarrow> P \<Longrightarrow> \<not> P \<longrightarrow> \<not> Q"
   by iprover
 
 lemma ex_mono: "(\<And>x. P x \<longrightarrow> Q x) \<Longrightarrow> (\<exists>x. P x) \<longrightarrow> (\<exists>x. Q x)"
   by iprover
 
 lemma all_mono: "(\<And>x. P x \<longrightarrow> Q x) \<Longrightarrow> (\<forall>x. P x) \<longrightarrow> (\<forall>x. Q x)"
   by iprover
 
 lemma Collect_mono: "(\<And>x. P x \<longrightarrow> Q x) \<Longrightarrow> Collect P \<subseteq> Collect Q"
   by blast
 
 lemma Int_Collect_mono: "A \<subseteq> B \<Longrightarrow> (\<And>x. x \<in> A \<Longrightarrow> P x \<longrightarrow> Q x) \<Longrightarrow> A \<inter> Collect P \<subseteq> B \<inter> Collect Q"
   by blast
 
 lemmas basic_monos =
   subset_refl imp_refl disj_mono conj_mono ex_mono Collect_mono in_mono
 
 lemma eq_to_mono: "a = b \<Longrightarrow> c = d \<Longrightarrow> b \<longrightarrow> d \<Longrightarrow> a \<longrightarrow> c"
   by iprover
 
 
 subsubsection \<open>Inverse image of a function\<close>
 
 definition vimage :: "('a \<Rightarrow> 'b) \<Rightarrow> 'b set \<Rightarrow> 'a set"  (infixr "-`" 90)
   where "f -` B \<equiv> {x. f x \<in> B}"
 
 lemma vimage_eq [simp]: "a \<in> f -` B \<longleftrightarrow> f a \<in> B"
   unfolding vimage_def by blast
 
 lemma vimage_singleton_eq: "a \<in> f -` {b} \<longleftrightarrow> f a = b"
   by simp
 
 lemma vimageI [intro]: "f a = b \<Longrightarrow> b \<in> B \<Longrightarrow> a \<in> f -` B"
   unfolding vimage_def by blast
 
 lemma vimageI2: "f a \<in> A \<Longrightarrow> a \<in> f -` A"
   unfolding vimage_def by fast
 
 lemma vimageE [elim!]: "a \<in> f -` B \<Longrightarrow> (\<And>x. f a = x \<Longrightarrow> x \<in> B \<Longrightarrow> P) \<Longrightarrow> P"
   unfolding vimage_def by blast
 
 lemma vimageD: "a \<in> f -` A \<Longrightarrow> f a \<in> A"
   unfolding vimage_def by fast
 
 lemma vimage_empty [simp]: "f -` {} = {}"
   by blast
 
 lemma vimage_Compl: "f -` (- A) = - (f -` A)"
   by blast
 
 lemma vimage_Un [simp]: "f -` (A \<union> B) = (f -` A) \<union> (f -` B)"
   by blast
 
 lemma vimage_Int [simp]: "f -` (A \<inter> B) = (f -` A) \<inter> (f -` B)"
   by fast
 
 lemma vimage_Collect_eq [simp]: "f -` Collect P = {y. P (f y)}"
   by blast
 
 lemma vimage_Collect: "(\<And>x. P (f x) = Q x) \<Longrightarrow> f -` (Collect P) = Collect Q"
   by blast
 
 lemma vimage_insert: "f -` (insert a B) = (f -` {a}) \<union> (f -` B)"
   \<comment> \<open>NOT suitable for rewriting because of the recurrence of \<open>{a}\<close>.\<close>
   by blast
 
 lemma vimage_Diff: "f -` (A - B) = (f -` A) - (f -` B)"
   by blast
 
 lemma vimage_UNIV [simp]: "f -` UNIV = UNIV"
   by blast
 
 lemma vimage_mono: "A \<subseteq> B \<Longrightarrow> f -` A \<subseteq> f -` B"
   \<comment> \<open>monotonicity\<close>
   by blast
 
 lemma vimage_image_eq: "f -` (f ` A) = {y. \<exists>x\<in>A. f x = f y}"
   by (blast intro: sym)
 
 lemma image_vimage_subset: "f ` (f -` A) \<subseteq> A"
   by blast
 
 lemma image_vimage_eq [simp]: "f ` (f -` A) = A \<inter> range f"
   by blast
 
 lemma image_subset_iff_subset_vimage: "f ` A \<subseteq> B \<longleftrightarrow> A \<subseteq> f -` B"
   by blast
 
 lemma vimage_const [simp]: "((\<lambda>x. c) -` A) = (if c \<in> A then UNIV else {})"
   by auto
 
 lemma vimage_if [simp]: "((\<lambda>x. if x \<in> B then c else d) -` A) =
    (if c \<in> A then (if d \<in> A then UNIV else B)
     else if d \<in> A then - B else {})"
   by (auto simp add: vimage_def)
 
 lemma vimage_inter_cong: "(\<And> w. w \<in> S \<Longrightarrow> f w = g w) \<Longrightarrow> f -` y \<inter> S = g -` y \<inter> S"
   by auto
 
 lemma vimage_ident [simp]: "(\<lambda>x. x) -` Y = Y"
   by blast
 
 
 subsubsection \<open>Singleton sets\<close>
 
 definition is_singleton :: "'a set \<Rightarrow> bool"
   where "is_singleton A \<longleftrightarrow> (\<exists>x. A = {x})"
 
 lemma is_singletonI [simp, intro!]: "is_singleton {x}"
   unfolding is_singleton_def by simp
 
 lemma is_singletonI': "A \<noteq> {} \<Longrightarrow> (\<And>x y. x \<in> A \<Longrightarrow> y \<in> A \<Longrightarrow> x = y) \<Longrightarrow> is_singleton A"
   unfolding is_singleton_def by blast
 
 lemma is_singletonE: "is_singleton A \<Longrightarrow> (\<And>x. A = {x} \<Longrightarrow> P) \<Longrightarrow> P"
   unfolding is_singleton_def by blast
 
 
 subsubsection \<open>Getting the contents of a singleton set\<close>
 
 definition the_elem :: "'a set \<Rightarrow> 'a"
   where "the_elem X = (THE x. X = {x})"
 
 lemma the_elem_eq [simp]: "the_elem {x} = x"
   by (simp add: the_elem_def)
 
 lemma is_singleton_the_elem: "is_singleton A \<longleftrightarrow> A = {the_elem A}"
   by (auto simp: is_singleton_def)
 
 lemma the_elem_image_unique:
   assumes "A \<noteq> {}"
     and *: "\<And>y. y \<in> A \<Longrightarrow> f y = f x"
   shows "the_elem (f ` A) = f x"
   unfolding the_elem_def
 proof (rule the1_equality)
   from \<open>A \<noteq> {}\<close> obtain y where "y \<in> A" by auto
   with * have "f x = f y" by simp
   with \<open>y \<in> A\<close> have "f x \<in> f ` A" by blast
   with * show "f ` A = {f x}" by auto
   then show "\<exists>!x. f ` A = {x}" by auto
 qed
 
 
 subsubsection \<open>Least value operator\<close>
 
 lemma Least_mono: "mono f \<Longrightarrow> \<exists>x\<in>S. \<forall>y\<in>S. x \<le> y \<Longrightarrow> (LEAST y. y \<in> f ` S) = f (LEAST x. x \<in> S)"
   for f :: "'a::order \<Rightarrow> 'b::order"
   \<comment> \<open>Courtesy of Stephan Merz\<close>
   apply clarify
   apply (erule_tac P = "\<lambda>x. x \<in> S" in LeastI2_order)
    apply fast
   apply (rule LeastI2_order)
     apply (auto elim: monoD intro!: order_antisym)
   done
 
 
 subsubsection \<open>Monad operation\<close>
 
 definition bind :: "'a set \<Rightarrow> ('a \<Rightarrow> 'b set) \<Rightarrow> 'b set"
   where "bind A f = {x. \<exists>B \<in> f`A. x \<in> B}"
 
 hide_const (open) bind
 
 lemma bind_bind: "Set.bind (Set.bind A B) C = Set.bind A (\<lambda>x. Set.bind (B x) C)"
   for A :: "'a set"
   by (auto simp: bind_def)
 
 lemma empty_bind [simp]: "Set.bind {} f = {}"
   by (simp add: bind_def)
 
 lemma nonempty_bind_const: "A \<noteq> {} \<Longrightarrow> Set.bind A (\<lambda>_. B) = B"
   by (auto simp: bind_def)
 
 lemma bind_const: "Set.bind A (\<lambda>_. B) = (if A = {} then {} else B)"
   by (auto simp: bind_def)
 
 lemma bind_singleton_conv_image: "Set.bind A (\<lambda>x. {f x}) = f ` A"
   by (auto simp: bind_def)
 
 
 subsubsection \<open>Operations for execution\<close>
 
 definition is_empty :: "'a set \<Rightarrow> bool"
   where [code_abbrev]: "is_empty A \<longleftrightarrow> A = {}"
 
 hide_const (open) is_empty
 
 definition remove :: "'a \<Rightarrow> 'a set \<Rightarrow> 'a set"
   where [code_abbrev]: "remove x A = A - {x}"
 
 hide_const (open) remove
 
 lemma member_remove [simp]: "x \<in> Set.remove y A \<longleftrightarrow> x \<in> A \<and> x \<noteq> y"
   by (simp add: remove_def)
 
 definition filter :: "('a \<Rightarrow> bool) \<Rightarrow> 'a set \<Rightarrow> 'a set"
   where [code_abbrev]: "filter P A = {a \<in> A. P a}"
 
 hide_const (open) filter
 
 lemma member_filter [simp]: "x \<in> Set.filter P A \<longleftrightarrow> x \<in> A \<and> P x"
   by (simp add: filter_def)
 
 instantiation set :: (equal) equal
 begin
 
 definition "HOL.equal A B \<longleftrightarrow> A \<subseteq> B \<and> B \<subseteq> A"
 
 instance by standard (auto simp add: equal_set_def)
 
 end
 
 
 text \<open>Misc\<close>
 
 definition pairwise :: "('a \<Rightarrow> 'a \<Rightarrow> bool) \<Rightarrow> 'a set \<Rightarrow> bool"
   where "pairwise R S \<longleftrightarrow> (\<forall>x \<in> S. \<forall>y \<in> S. x \<noteq> y \<longrightarrow> R x y)"
 
 lemma pairwise_alt: "pairwise R S \<longleftrightarrow> (\<forall>x\<in>S. \<forall>y\<in>S-{x}. R x y)"
 by (auto simp add: pairwise_def)
 
 lemma pairwise_trivial [simp]: "pairwise (\<lambda>i j. j \<noteq> i) I"
   by (auto simp: pairwise_def)
 
 lemma pairwiseI [intro?]:
   "pairwise R S" if "\<And>x y. x \<in> S \<Longrightarrow> y \<in> S \<Longrightarrow> x \<noteq> y \<Longrightarrow> R x y"
   using that by (simp add: pairwise_def)
 
 lemma pairwiseD:
   "R x y" and "R y x"
   if "pairwise R S" "x \<in> S" and "y \<in> S" and "x \<noteq> y"
   using that by (simp_all add: pairwise_def)
 
 lemma pairwise_empty [simp]: "pairwise P {}"
   by (simp add: pairwise_def)
 
 lemma pairwise_singleton [simp]: "pairwise P {A}"
   by (simp add: pairwise_def)
 
 lemma pairwise_insert:
   "pairwise r (insert x s) \<longleftrightarrow> (\<forall>y. y \<in> s \<and> y \<noteq> x \<longrightarrow> r x y \<and> r y x) \<and> pairwise r s"
   by (force simp: pairwise_def)
 
 lemma pairwise_subset: "pairwise P S \<Longrightarrow> T \<subseteq> S \<Longrightarrow> pairwise P T"
   by (force simp: pairwise_def)
 
 lemma pairwise_mono: "\<lbrakk>pairwise P A; \<And>x y. P x y \<Longrightarrow> Q x y; B \<subseteq> A\<rbrakk> \<Longrightarrow> pairwise Q B"
   by (fastforce simp: pairwise_def)
 
 lemma pairwise_imageI:
   "pairwise P (f ` A)"
   if "\<And>x y. x \<in> A \<Longrightarrow> y \<in> A \<Longrightarrow> x \<noteq> y \<Longrightarrow> f x \<noteq> f y \<Longrightarrow> P (f x) (f y)"
   using that by (auto intro: pairwiseI)
 
 lemma pairwise_image: "pairwise r (f ` s) \<longleftrightarrow> pairwise (\<lambda>x y. (f x \<noteq> f y) \<longrightarrow> r (f x) (f y)) s"
   by (force simp: pairwise_def)
 
 definition disjnt :: "'a set \<Rightarrow> 'a set \<Rightarrow> bool"
   where "disjnt A B \<longleftrightarrow> A \<inter> B = {}"
 
 lemma disjnt_self_iff_empty [simp]: "disjnt S S \<longleftrightarrow> S = {}"
   by (auto simp: disjnt_def)
 
 lemma disjnt_iff: "disjnt A B \<longleftrightarrow> (\<forall>x. \<not> (x \<in> A \<and> x \<in> B))"
   by (force simp: disjnt_def)
 
 lemma disjnt_sym: "disjnt A B \<Longrightarrow> disjnt B A"
   using disjnt_iff by blast
 
 lemma disjnt_empty1 [simp]: "disjnt {} A" and disjnt_empty2 [simp]: "disjnt A {}"
   by (auto simp: disjnt_def)
 
 lemma disjnt_insert1 [simp]: "disjnt (insert a X) Y \<longleftrightarrow> a \<notin> Y \<and> disjnt X Y"
   by (simp add: disjnt_def)
 
 lemma disjnt_insert2 [simp]: "disjnt Y (insert a X) \<longleftrightarrow> a \<notin> Y \<and> disjnt Y X"
   by (simp add: disjnt_def)
 
 lemma disjnt_subset1 : "\<lbrakk>disjnt X Y; Z \<subseteq> X\<rbrakk> \<Longrightarrow> disjnt Z Y"
   by (auto simp: disjnt_def)
 
 lemma disjnt_subset2 : "\<lbrakk>disjnt X Y; Z \<subseteq> Y\<rbrakk> \<Longrightarrow> disjnt X Z"
   by (auto simp: disjnt_def)
 
 lemma disjnt_Un1 [simp]: "disjnt (A \<union> B) C \<longleftrightarrow> disjnt A C \<and> disjnt B C"
   by (auto simp: disjnt_def)
 
 lemma disjnt_Un2 [simp]: "disjnt C (A \<union> B) \<longleftrightarrow> disjnt C A \<and> disjnt C B"
   by (auto simp: disjnt_def)
 
 lemma disjoint_image_subset: "\<lbrakk>pairwise disjnt \<A>; \<And>X. X \<in> \<A> \<Longrightarrow> f X \<subseteq> X\<rbrakk> \<Longrightarrow> pairwise disjnt (f `\<A>)"
   unfolding disjnt_def pairwise_def by fast
 
 lemma pairwise_disjnt_iff: "pairwise disjnt \<A> \<longleftrightarrow> (\<forall>x. \<exists>\<^sub>\<le>\<^sub>1 X. X \<in> \<A> \<and> x \<in> X)"
   by (auto simp: Uniq_def disjnt_iff pairwise_def)
 
+lemma disjnt_insert: \<^marker>\<open>contributor \<open>Lars Hupel\<close>\<close>
+  \<open>disjnt (insert x M) N\<close> if \<open>x \<notin> N\<close> \<open>disjnt M N\<close>
+  using that by (simp add: disjnt_def)
+
 lemma Int_emptyI: "(\<And>x. x \<in> A \<Longrightarrow> x \<in> B \<Longrightarrow> False) \<Longrightarrow> A \<inter> B = {}"
   by blast
 
 lemma in_image_insert_iff:
   assumes "\<And>C. C \<in> B \<Longrightarrow> x \<notin> C"
   shows "A \<in> insert x ` B \<longleftrightarrow> x \<in> A \<and> A - {x} \<in> B" (is "?P \<longleftrightarrow> ?Q")
 proof
   assume ?P then show ?Q
     using assms by auto
 next
   assume ?Q
   then have "x \<in> A" and "A - {x} \<in> B"
     by simp_all
   from \<open>A - {x} \<in> B\<close> have "insert x (A - {x}) \<in> insert x ` B"
     by (rule imageI)
   also from \<open>x \<in> A\<close>
   have "insert x (A - {x}) = A"
     by auto
   finally show ?P .
 qed
 
 hide_const (open) member not_member
 
 lemmas equalityI = subset_antisym
 lemmas set_mp = subsetD
 lemmas set_rev_mp = rev_subsetD
 
 ML \<open>
 val Ball_def = @{thm Ball_def}
 val Bex_def = @{thm Bex_def}
 val CollectD = @{thm CollectD}
 val CollectE = @{thm CollectE}
 val CollectI = @{thm CollectI}
 val Collect_conj_eq = @{thm Collect_conj_eq}
 val Collect_mem_eq = @{thm Collect_mem_eq}
 val IntD1 = @{thm IntD1}
 val IntD2 = @{thm IntD2}
 val IntE = @{thm IntE}
 val IntI = @{thm IntI}
 val Int_Collect = @{thm Int_Collect}
 val UNIV_I = @{thm UNIV_I}
 val UNIV_witness = @{thm UNIV_witness}
 val UnE = @{thm UnE}
 val UnI1 = @{thm UnI1}
 val UnI2 = @{thm UnI2}
 val ballE = @{thm ballE}
 val ballI = @{thm ballI}
 val bexCI = @{thm bexCI}
 val bexE = @{thm bexE}
 val bexI = @{thm bexI}
 val bex_triv = @{thm bex_triv}
 val bspec = @{thm bspec}
 val contra_subsetD = @{thm contra_subsetD}
 val equalityCE = @{thm equalityCE}
 val equalityD1 = @{thm equalityD1}
 val equalityD2 = @{thm equalityD2}
 val equalityE = @{thm equalityE}
 val equalityI = @{thm equalityI}
 val imageE = @{thm imageE}
 val imageI = @{thm imageI}
 val image_Un = @{thm image_Un}
 val image_insert = @{thm image_insert}
 val insert_commute = @{thm insert_commute}
 val insert_iff = @{thm insert_iff}
 val mem_Collect_eq = @{thm mem_Collect_eq}
 val rangeE = @{thm rangeE}
 val rangeI = @{thm rangeI}
 val range_eqI = @{thm range_eqI}
 val subsetCE = @{thm subsetCE}
 val subsetD = @{thm subsetD}
 val subsetI = @{thm subsetI}
 val subset_refl = @{thm subset_refl}
 val subset_trans = @{thm subset_trans}
 val vimageD = @{thm vimageD}
 val vimageE = @{thm vimageE}
 val vimageI = @{thm vimageI}
 val vimageI2 = @{thm vimageI2}
 val vimage_Collect = @{thm vimage_Collect}
 val vimage_Int = @{thm vimage_Int}
 val vimage_Un = @{thm vimage_Un}
 \<close>
 
 end