--- a/src/Doc/Main/Main_Doc.thy Sat Dec 14 20:46:36 2013 +0100
+++ b/src/Doc/Main/Main_Doc.thy Sun Dec 15 15:10:14 2013 +0100
@@ -407,8 +407,8 @@
@{const Finite_Set.finite} & @{term_type_only Finite_Set.finite "'a set\<Rightarrow>bool"}\\
@{const Finite_Set.card} & @{term_type_only Finite_Set.card "'a set => nat"}\\
@{const Finite_Set.fold} & @{term_type_only Finite_Set.fold "('a \<Rightarrow> 'b \<Rightarrow> 'b) \<Rightarrow> 'b \<Rightarrow> 'a set \<Rightarrow> 'b"}\\
-@{const Big_Operators.setsum} & @{term_type_only Big_Operators.setsum "('a => 'b) => 'a set => 'b::comm_monoid_add"}\\
-@{const Big_Operators.setprod} & @{term_type_only Big_Operators.setprod "('a => 'b) => 'a set => 'b::comm_monoid_mult"}\\
+@{const Groups_Big.setsum} & @{term_type_only Groups_Big.setsum "('a => 'b) => 'a set => 'b::comm_monoid_add"}\\
+@{const Groups_Big.setprod} & @{term_type_only Groups_Big.setprod "('a => 'b) => 'a set => 'b::comm_monoid_mult"}\\
\end{supertabular}
--- a/src/HOL/Big_Operators.thy Sat Dec 14 20:46:36 2013 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,2193 +0,0 @@
-(* Title: HOL/Big_Operators.thy
- Author: Tobias Nipkow, Lawrence C Paulson and Markus Wenzel
- with contributions by Jeremy Avigad
-*)
-
-header {* Big operators and finite (non-empty) sets *}
-
-theory Big_Operators
-imports Finite_Set Metis
-begin
-
-subsection {* Generic monoid operation over a set *}
-
-no_notation times (infixl "*" 70)
-no_notation Groups.one ("1")
-
-locale comm_monoid_set = comm_monoid
-begin
-
-interpretation comp_fun_commute f
- by default (simp add: fun_eq_iff left_commute)
-
-interpretation comp_fun_commute "f \<circ> g"
- by (rule comp_comp_fun_commute)
-
-definition F :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'a"
-where
- eq_fold: "F g A = Finite_Set.fold (f \<circ> g) 1 A"
-
-lemma infinite [simp]:
- "\<not> finite A \<Longrightarrow> F g A = 1"
- by (simp add: eq_fold)
-
-lemma empty [simp]:
- "F g {} = 1"
- by (simp add: eq_fold)
-
-lemma insert [simp]:
- assumes "finite A" and "x \<notin> A"
- shows "F g (insert x A) = g x * F g A"
- using assms by (simp add: eq_fold)
-
-lemma remove:
- assumes "finite A" and "x \<in> A"
- shows "F g A = g x * F g (A - {x})"
-proof -
- from `x \<in> A` obtain B where A: "A = insert x B" and "x \<notin> B"
- by (auto dest: mk_disjoint_insert)
- moreover from `finite A` A have "finite B" by simp
- ultimately show ?thesis by simp
-qed
-
-lemma insert_remove:
- assumes "finite A"
- shows "F g (insert x A) = g x * F g (A - {x})"
- using assms by (cases "x \<in> A") (simp_all add: remove insert_absorb)
-
-lemma neutral:
- assumes "\<forall>x\<in>A. g x = 1"
- shows "F g A = 1"
- using assms by (induct A rule: infinite_finite_induct) simp_all
-
-lemma neutral_const [simp]:
- "F (\<lambda>_. 1) A = 1"
- by (simp add: neutral)
-
-lemma union_inter:
- assumes "finite A" and "finite B"
- shows "F g (A \<union> B) * F g (A \<inter> B) = F g A * F g B"
- -- {* The reversed orientation looks more natural, but LOOPS as a simprule! *}
-using assms proof (induct A)
- case empty then show ?case by simp
-next
- case (insert x A) then show ?case
- by (auto simp add: insert_absorb Int_insert_left commute [of _ "g x"] assoc left_commute)
-qed
-
-corollary union_inter_neutral:
- assumes "finite A" and "finite B"
- and I0: "\<forall>x \<in> A \<inter> B. g x = 1"
- shows "F g (A \<union> B) = F g A * F g B"
- using assms by (simp add: union_inter [symmetric] neutral)
-
-corollary union_disjoint:
- assumes "finite A" and "finite B"
- assumes "A \<inter> B = {}"
- shows "F g (A \<union> B) = F g A * F g B"
- using assms by (simp add: union_inter_neutral)
-
-lemma subset_diff:
- "B \<subseteq> A \<Longrightarrow> finite A \<Longrightarrow> F g A = F g (A - B) * F g B"
- by (metis Diff_partition union_disjoint Diff_disjoint finite_Un inf_commute sup_commute)
-
-lemma reindex:
- assumes "inj_on h A"
- shows "F g (h ` A) = F (g \<circ> h) A"
-proof (cases "finite A")
- case True
- with assms show ?thesis by (simp add: eq_fold fold_image comp_assoc)
-next
- case False with assms have "\<not> finite (h ` A)" by (blast dest: finite_imageD)
- with False show ?thesis by simp
-qed
-
-lemma cong:
- assumes "A = B"
- assumes g_h: "\<And>x. x \<in> B \<Longrightarrow> g x = h x"
- shows "F g A = F h B"
-proof (cases "finite A")
- case True
- then have "\<And>C. C \<subseteq> A \<longrightarrow> (\<forall>x\<in>C. g x = h x) \<longrightarrow> F g C = F h C"
- proof induct
- case empty then show ?case by simp
- next
- case (insert x F) then show ?case apply -
- apply (simp add: subset_insert_iff, clarify)
- apply (subgoal_tac "finite C")
- prefer 2 apply (blast dest: finite_subset [rotated])
- apply (subgoal_tac "C = insert x (C - {x})")
- prefer 2 apply blast
- apply (erule ssubst)
- apply (simp add: Ball_def del: insert_Diff_single)
- done
- qed
- with `A = B` g_h show ?thesis by simp
-next
- case False
- with `A = B` show ?thesis by simp
-qed
-
-lemma strong_cong [cong]:
- assumes "A = B" "\<And>x. x \<in> B =simp=> g x = h x"
- shows "F (\<lambda>x. g x) A = F (\<lambda>x. h x) B"
- by (rule cong) (insert assms, simp_all add: simp_implies_def)
-
-lemma UNION_disjoint:
- assumes "finite I" and "\<forall>i\<in>I. finite (A i)"
- and "\<forall>i\<in>I. \<forall>j\<in>I. i \<noteq> j \<longrightarrow> A i \<inter> A j = {}"
- shows "F g (UNION I A) = F (\<lambda>x. F g (A x)) I"
-apply (insert assms)
-apply (induct rule: finite_induct)
-apply simp
-apply atomize
-apply (subgoal_tac "\<forall>i\<in>Fa. x \<noteq> i")
- prefer 2 apply blast
-apply (subgoal_tac "A x Int UNION Fa A = {}")
- prefer 2 apply blast
-apply (simp add: union_disjoint)
-done
-
-lemma Union_disjoint:
- assumes "\<forall>A\<in>C. finite A" "\<forall>A\<in>C. \<forall>B\<in>C. A \<noteq> B \<longrightarrow> A \<inter> B = {}"
- shows "F g (Union C) = F (F g) C"
-proof cases
- assume "finite C"
- from UNION_disjoint [OF this assms]
- show ?thesis
- by (simp add: SUP_def)
-qed (auto dest: finite_UnionD intro: infinite)
-
-lemma distrib:
- "F (\<lambda>x. g x * h x) A = F g A * F h A"
- using assms by (induct A rule: infinite_finite_induct) (simp_all add: assoc commute left_commute)
-
-lemma Sigma:
- "finite A \<Longrightarrow> \<forall>x\<in>A. finite (B x) \<Longrightarrow> F (\<lambda>x. F (g x) (B x)) A = F (split g) (SIGMA x:A. B x)"
-apply (subst Sigma_def)
-apply (subst UNION_disjoint, assumption, simp)
- apply blast
-apply (rule cong)
-apply rule
-apply (simp add: fun_eq_iff)
-apply (subst UNION_disjoint, simp, simp)
- apply blast
-apply (simp add: comp_def)
-done
-
-lemma related:
- assumes Re: "R 1 1"
- and Rop: "\<forall>x1 y1 x2 y2. R x1 x2 \<and> R y1 y2 \<longrightarrow> R (x1 * y1) (x2 * y2)"
- and fS: "finite S" and Rfg: "\<forall>x\<in>S. R (h x) (g x)"
- shows "R (F h S) (F g S)"
- using fS by (rule finite_subset_induct) (insert assms, auto)
-
-lemma eq_general:
- assumes h: "\<forall>y\<in>S'. \<exists>!x. x \<in> S \<and> h x = y"
- and f12: "\<forall>x\<in>S. h x \<in> S' \<and> f2 (h x) = f1 x"
- shows "F f1 S = F f2 S'"
-proof-
- from h f12 have hS: "h ` S = S'" by blast
- {fix x y assume H: "x \<in> S" "y \<in> S" "h x = h y"
- from f12 h H have "x = y" by auto }
- hence hinj: "inj_on h S" unfolding inj_on_def Ex1_def by blast
- from f12 have th: "\<And>x. x \<in> S \<Longrightarrow> (f2 \<circ> h) x = f1 x" by auto
- from hS have "F f2 S' = F f2 (h ` S)" by simp
- also have "\<dots> = F (f2 o h) S" using reindex [OF hinj, of f2] .
- also have "\<dots> = F f1 S " using th cong [of _ _ "f2 o h" f1]
- by blast
- finally show ?thesis ..
-qed
-
-lemma eq_general_reverses:
- assumes kh: "\<And>y. y \<in> T \<Longrightarrow> k y \<in> S \<and> h (k y) = y"
- and hk: "\<And>x. x \<in> S \<Longrightarrow> h x \<in> T \<and> k (h x) = x \<and> g (h x) = j x"
- shows "F j S = F g T"
- (* metis solves it, but not yet available here *)
- apply (rule eq_general [of T S h g j])
- apply (rule ballI)
- apply (frule kh)
- apply (rule ex1I[])
- apply blast
- apply clarsimp
- apply (drule hk) apply simp
- apply (rule sym)
- apply (erule conjunct1[OF conjunct2[OF hk]])
- apply (rule ballI)
- apply (drule hk)
- apply blast
- done
-
-lemma mono_neutral_cong_left:
- assumes "finite T" and "S \<subseteq> T" and "\<forall>i \<in> T - S. h i = 1"
- and "\<And>x. x \<in> S \<Longrightarrow> g x = h x" shows "F g S = F h T"
-proof-
- have eq: "T = S \<union> (T - S)" using `S \<subseteq> T` by blast
- have d: "S \<inter> (T - S) = {}" using `S \<subseteq> T` by blast
- from `finite T` `S \<subseteq> T` have f: "finite S" "finite (T - S)"
- by (auto intro: finite_subset)
- show ?thesis using assms(4)
- by (simp add: union_disjoint [OF f d, unfolded eq [symmetric]] neutral [OF assms(3)])
-qed
-
-lemma mono_neutral_cong_right:
- "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1; \<And>x. x \<in> S \<Longrightarrow> g x = h x \<rbrakk>
- \<Longrightarrow> F g T = F h S"
- by (auto intro!: mono_neutral_cong_left [symmetric])
-
-lemma mono_neutral_left:
- "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1 \<rbrakk> \<Longrightarrow> F g S = F g T"
- by (blast intro: mono_neutral_cong_left)
-
-lemma mono_neutral_right:
- "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1 \<rbrakk> \<Longrightarrow> F g T = F g S"
- by (blast intro!: mono_neutral_left [symmetric])
-
-lemma delta:
- assumes fS: "finite S"
- shows "F (\<lambda>k. if k = a then b k else 1) S = (if a \<in> S then b a else 1)"
-proof-
- let ?f = "(\<lambda>k. if k=a then b k else 1)"
- { assume a: "a \<notin> S"
- hence "\<forall>k\<in>S. ?f k = 1" by simp
- hence ?thesis using a by simp }
- moreover
- { assume a: "a \<in> S"
- let ?A = "S - {a}"
- let ?B = "{a}"
- have eq: "S = ?A \<union> ?B" using a by blast
- have dj: "?A \<inter> ?B = {}" by simp
- from fS have fAB: "finite ?A" "finite ?B" by auto
- have "F ?f S = F ?f ?A * F ?f ?B"
- using union_disjoint [OF fAB dj, of ?f, unfolded eq [symmetric]]
- by simp
- then have ?thesis using a by simp }
- ultimately show ?thesis by blast
-qed
-
-lemma delta':
- assumes fS: "finite S"
- shows "F (\<lambda>k. if a = k then b k else 1) S = (if a \<in> S then b a else 1)"
- using delta [OF fS, of a b, symmetric] by (auto intro: cong)
-
-lemma If_cases:
- fixes P :: "'b \<Rightarrow> bool" and g h :: "'b \<Rightarrow> 'a"
- assumes fA: "finite A"
- shows "F (\<lambda>x. if P x then h x else g x) A =
- F h (A \<inter> {x. P x}) * F g (A \<inter> - {x. P x})"
-proof -
- have a: "A = A \<inter> {x. P x} \<union> A \<inter> -{x. P x}"
- "(A \<inter> {x. P x}) \<inter> (A \<inter> -{x. P x}) = {}"
- by blast+
- from fA
- have f: "finite (A \<inter> {x. P x})" "finite (A \<inter> -{x. P x})" by auto
- let ?g = "\<lambda>x. if P x then h x else g x"
- from union_disjoint [OF f a(2), of ?g] a(1)
- show ?thesis
- by (subst (1 2) cong) simp_all
-qed
-
-lemma cartesian_product:
- "F (\<lambda>x. F (g x) B) A = F (split g) (A <*> B)"
-apply (rule sym)
-apply (cases "finite A")
- apply (cases "finite B")
- apply (simp add: Sigma)
- apply (cases "A={}", simp)
- apply simp
-apply (auto intro: infinite dest: finite_cartesian_productD2)
-apply (cases "B = {}") apply (auto intro: infinite dest: finite_cartesian_productD1)
-done
-
-end
-
-notation times (infixl "*" 70)
-notation Groups.one ("1")
-
-
-subsection {* Generalized summation over a set *}
-
-context comm_monoid_add
-begin
-
-definition setsum :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'a"
-where
- "setsum = comm_monoid_set.F plus 0"
-
-sublocale setsum!: comm_monoid_set plus 0
-where
- "comm_monoid_set.F plus 0 = setsum"
-proof -
- show "comm_monoid_set plus 0" ..
- then interpret setsum!: comm_monoid_set plus 0 .
- from setsum_def show "comm_monoid_set.F plus 0 = setsum" by rule
-qed
-
-abbreviation
- Setsum ("\<Sum>_" [1000] 999) where
- "\<Sum>A \<equiv> setsum (%x. x) A"
-
-end
-
-text{* Now: lot's of fancy syntax. First, @{term "setsum (%x. e) A"} is
-written @{text"\<Sum>x\<in>A. e"}. *}
-
-syntax
- "_setsum" :: "pttrn => 'a set => 'b => 'b::comm_monoid_add" ("(3SUM _:_. _)" [0, 51, 10] 10)
-syntax (xsymbols)
- "_setsum" :: "pttrn => 'a set => 'b => 'b::comm_monoid_add" ("(3\<Sum>_\<in>_. _)" [0, 51, 10] 10)
-syntax (HTML output)
- "_setsum" :: "pttrn => 'a set => 'b => 'b::comm_monoid_add" ("(3\<Sum>_\<in>_. _)" [0, 51, 10] 10)
-
-translations -- {* Beware of argument permutation! *}
- "SUM i:A. b" == "CONST setsum (%i. b) A"
- "\<Sum>i\<in>A. b" == "CONST setsum (%i. b) A"
-
-text{* Instead of @{term"\<Sum>x\<in>{x. P}. e"} we introduce the shorter
- @{text"\<Sum>x|P. e"}. *}
-
-syntax
- "_qsetsum" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3SUM _ |/ _./ _)" [0,0,10] 10)
-syntax (xsymbols)
- "_qsetsum" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Sum>_ | (_)./ _)" [0,0,10] 10)
-syntax (HTML output)
- "_qsetsum" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Sum>_ | (_)./ _)" [0,0,10] 10)
-
-translations
- "SUM x|P. t" => "CONST setsum (%x. t) {x. P}"
- "\<Sum>x|P. t" => "CONST setsum (%x. t) {x. P}"
-
-print_translation {*
-let
- fun setsum_tr' [Abs (x, Tx, t), Const (@{const_syntax Collect}, _) $ Abs (y, Ty, P)] =
- if x <> y then raise Match
- else
- let
- val x' = Syntax_Trans.mark_bound_body (x, Tx);
- val t' = subst_bound (x', t);
- val P' = subst_bound (x', P);
- in
- Syntax.const @{syntax_const "_qsetsum"} $ Syntax_Trans.mark_bound_abs (x, Tx) $ P' $ t'
- end
- | setsum_tr' _ = raise Match;
-in [(@{const_syntax setsum}, K setsum_tr')] end
-*}
-
-text {* TODO These are candidates for generalization *}
-
-context comm_monoid_add
-begin
-
-lemma setsum_reindex_id:
- "inj_on f B ==> setsum f B = setsum id (f ` B)"
- by (simp add: setsum.reindex)
-
-lemma setsum_reindex_nonzero:
- assumes fS: "finite S"
- and nz: "\<And>x y. x \<in> S \<Longrightarrow> y \<in> S \<Longrightarrow> x \<noteq> y \<Longrightarrow> f x = f y \<Longrightarrow> h (f x) = 0"
- shows "setsum h (f ` S) = setsum (h \<circ> f) S"
-using nz proof (induct rule: finite_induct [OF fS])
- case 1 thus ?case by simp
-next
- case (2 x F)
- { assume fxF: "f x \<in> f ` F" hence "\<exists>y \<in> F . f y = f x" by auto
- then obtain y where y: "y \<in> F" "f x = f y" by auto
- from "2.hyps" y have xy: "x \<noteq> y" by auto
- from "2.prems" [of x y] "2.hyps" xy y have h0: "h (f x) = 0" by simp
- have "setsum h (f ` insert x F) = setsum h (f ` F)" using fxF by auto
- also have "\<dots> = setsum (h o f) (insert x F)"
- unfolding setsum.insert[OF `finite F` `x\<notin>F`]
- using h0
- apply (simp cong del: setsum.strong_cong)
- apply (rule "2.hyps"(3))
- apply (rule_tac y="y" in "2.prems")
- apply simp_all
- done
- finally have ?case . }
- moreover
- { assume fxF: "f x \<notin> f ` F"
- have "setsum h (f ` insert x F) = h (f x) + setsum h (f ` F)"
- using fxF "2.hyps" by simp
- also have "\<dots> = setsum (h o f) (insert x F)"
- unfolding setsum.insert[OF `finite F` `x\<notin>F`]
- apply (simp cong del: setsum.strong_cong)
- apply (rule cong [OF refl [of "op + (h (f x))"]])
- apply (rule "2.hyps"(3))
- apply (rule_tac y="y" in "2.prems")
- apply simp_all
- done
- finally have ?case . }
- ultimately show ?case by blast
-qed
-
-lemma setsum_cong2:
- "(\<And>x. x \<in> A \<Longrightarrow> f x = g x) \<Longrightarrow> setsum f A = setsum g A"
- by (auto intro: setsum.cong)
-
-lemma setsum_reindex_cong:
- "[|inj_on f A; B = f ` A; !!a. a:A \<Longrightarrow> g a = h (f a)|]
- ==> setsum h B = setsum g A"
- by (simp add: setsum.reindex)
-
-lemma setsum_restrict_set:
- assumes fA: "finite A"
- shows "setsum f (A \<inter> B) = setsum (\<lambda>x. if x \<in> B then f x else 0) A"
-proof-
- from fA have fab: "finite (A \<inter> B)" by auto
- have aba: "A \<inter> B \<subseteq> A" by blast
- let ?g = "\<lambda>x. if x \<in> A\<inter>B then f x else 0"
- from setsum.mono_neutral_left [OF fA aba, of ?g]
- show ?thesis by simp
-qed
-
-lemma setsum_Union_disjoint:
- assumes "\<forall>A\<in>C. finite A" "\<forall>A\<in>C. \<forall>B\<in>C. A \<noteq> B \<longrightarrow> A Int B = {}"
- shows "setsum f (Union C) = setsum (setsum f) C"
- using assms by (fact setsum.Union_disjoint)
-
-lemma setsum_cartesian_product:
- "(\<Sum>x\<in>A. (\<Sum>y\<in>B. f x y)) = (\<Sum>(x,y) \<in> A <*> B. f x y)"
- by (fact setsum.cartesian_product)
-
-lemma setsum_UNION_zero:
- assumes fS: "finite S" and fSS: "\<forall>T \<in> S. finite T"
- and f0: "\<And>T1 T2 x. T1\<in>S \<Longrightarrow> T2\<in>S \<Longrightarrow> T1 \<noteq> T2 \<Longrightarrow> x \<in> T1 \<Longrightarrow> x \<in> T2 \<Longrightarrow> f x = 0"
- shows "setsum f (\<Union>S) = setsum (\<lambda>T. setsum f T) S"
- using fSS f0
-proof(induct rule: finite_induct[OF fS])
- case 1 thus ?case by simp
-next
- case (2 T F)
- then have fTF: "finite T" "\<forall>T\<in>F. finite T" "finite F" and TF: "T \<notin> F"
- and H: "setsum f (\<Union> F) = setsum (setsum f) F" by auto
- from fTF have fUF: "finite (\<Union>F)" by auto
- from "2.prems" TF fTF
- show ?case
- by (auto simp add: H [symmetric] intro: setsum.union_inter_neutral [OF fTF(1) fUF, of f])
-qed
-
-text {* Commuting outer and inner summation *}
-
-lemma setsum_commute:
- "(\<Sum>i\<in>A. \<Sum>j\<in>B. f i j) = (\<Sum>j\<in>B. \<Sum>i\<in>A. f i j)"
-proof (simp add: setsum_cartesian_product)
- have "(\<Sum>(x,y) \<in> A <*> B. f x y) =
- (\<Sum>(y,x) \<in> (%(i, j). (j, i)) ` (A \<times> B). f x y)"
- (is "?s = _")
- apply (simp add: setsum.reindex [where h = "%(i, j). (j, i)"] swap_inj_on)
- apply (simp add: split_def)
- done
- also have "... = (\<Sum>(y,x)\<in>B \<times> A. f x y)"
- (is "_ = ?t")
- apply (simp add: swap_product)
- done
- finally show "?s = ?t" .
-qed
-
-lemma setsum_Plus:
- fixes A :: "'a set" and B :: "'b set"
- assumes fin: "finite A" "finite B"
- shows "setsum f (A <+> B) = setsum (f \<circ> Inl) A + setsum (f \<circ> Inr) B"
-proof -
- have "A <+> B = Inl ` A \<union> Inr ` B" by auto
- moreover from fin have "finite (Inl ` A :: ('a + 'b) set)" "finite (Inr ` B :: ('a + 'b) set)"
- by auto
- moreover have "Inl ` A \<inter> Inr ` B = ({} :: ('a + 'b) set)" by auto
- moreover have "inj_on (Inl :: 'a \<Rightarrow> 'a + 'b) A" "inj_on (Inr :: 'b \<Rightarrow> 'a + 'b) B" by(auto intro: inj_onI)
- ultimately show ?thesis using fin by(simp add: setsum.union_disjoint setsum.reindex)
-qed
-
-end
-
-text {* TODO These are legacy *}
-
-lemma setsum_empty:
- "setsum f {} = 0"
- by (fact setsum.empty)
-
-lemma setsum_insert:
- "finite F ==> a \<notin> F ==> setsum f (insert a F) = f a + setsum f F"
- by (fact setsum.insert)
-
-lemma setsum_infinite:
- "~ finite A ==> setsum f A = 0"
- by (fact setsum.infinite)
-
-lemma setsum_reindex:
- "inj_on f B \<Longrightarrow> setsum h (f ` B) = setsum (h \<circ> f) B"
- by (fact setsum.reindex)
-
-lemma setsum_cong:
- "A = B ==> (!!x. x:B ==> f x = g x) ==> setsum f A = setsum g B"
- by (fact setsum.cong)
-
-lemma strong_setsum_cong:
- "A = B ==> (!!x. x:B =simp=> f x = g x)
- ==> setsum (%x. f x) A = setsum (%x. g x) B"
- by (fact setsum.strong_cong)
-
-lemmas setsum_0 = setsum.neutral_const
-lemmas setsum_0' = setsum.neutral
-
-lemma setsum_Un_Int: "finite A ==> finite B ==>
- setsum g (A Un B) + setsum g (A Int B) = setsum g A + setsum g B"
- -- {* The reversed orientation looks more natural, but LOOPS as a simprule! *}
- by (fact setsum.union_inter)
-
-lemma setsum_Un_disjoint: "finite A ==> finite B
- ==> A Int B = {} ==> setsum g (A Un B) = setsum g A + setsum g B"
- by (fact setsum.union_disjoint)
-
-lemma setsum_subset_diff: "\<lbrakk> B \<subseteq> A; finite A \<rbrakk> \<Longrightarrow>
- setsum f A = setsum f (A - B) + setsum f B"
- by (fact setsum.subset_diff)
-
-lemma setsum_mono_zero_left:
- "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. f i = 0 \<rbrakk> \<Longrightarrow> setsum f S = setsum f T"
- by (fact setsum.mono_neutral_left)
-
-lemmas setsum_mono_zero_right = setsum.mono_neutral_right
-
-lemma setsum_mono_zero_cong_left:
- "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 0; \<And>x. x \<in> S \<Longrightarrow> f x = g x \<rbrakk>
- \<Longrightarrow> setsum f S = setsum g T"
- by (fact setsum.mono_neutral_cong_left)
-
-lemmas setsum_mono_zero_cong_right = setsum.mono_neutral_cong_right
-
-lemma setsum_delta: "finite S \<Longrightarrow>
- setsum (\<lambda>k. if k=a then b k else 0) S = (if a \<in> S then b a else 0)"
- by (fact setsum.delta)
-
-lemma setsum_delta': "finite S \<Longrightarrow>
- setsum (\<lambda>k. if a = k then b k else 0) S = (if a\<in> S then b a else 0)"
- by (fact setsum.delta')
-
-lemma setsum_cases:
- assumes "finite A"
- shows "setsum (\<lambda>x. if P x then f x else g x) A =
- setsum f (A \<inter> {x. P x}) + setsum g (A \<inter> - {x. P x})"
- using assms by (fact setsum.If_cases)
-
-(*But we can't get rid of finite I. If infinite, although the rhs is 0,
- the lhs need not be, since UNION I A could still be finite.*)
-lemma setsum_UN_disjoint:
- assumes "finite I" and "ALL i:I. finite (A i)"
- and "ALL i:I. ALL j:I. i \<noteq> j --> A i Int A j = {}"
- shows "setsum f (UNION I A) = (\<Sum>i\<in>I. setsum f (A i))"
- using assms by (fact setsum.UNION_disjoint)
-
-(*But we can't get rid of finite A. If infinite, although the lhs is 0,
- the rhs need not be, since SIGMA A B could still be finite.*)
-lemma setsum_Sigma:
- assumes "finite A" and "ALL x:A. finite (B x)"
- shows "(\<Sum>x\<in>A. (\<Sum>y\<in>B x. f x y)) = (\<Sum>(x,y)\<in>(SIGMA x:A. B x). f x y)"
- using assms by (fact setsum.Sigma)
-
-lemma setsum_addf: "setsum (%x. f x + g x) A = (setsum f A + setsum g A)"
- by (fact setsum.distrib)
-
-lemma setsum_Un_zero:
- "\<lbrakk> finite S; finite T; \<forall>x \<in> S\<inter>T. f x = 0 \<rbrakk> \<Longrightarrow>
- setsum f (S \<union> T) = setsum f S + setsum f T"
- by (fact setsum.union_inter_neutral)
-
-lemma setsum_eq_general_reverses:
- assumes fS: "finite S" and fT: "finite T"
- and kh: "\<And>y. y \<in> T \<Longrightarrow> k y \<in> S \<and> h (k y) = y"
- and hk: "\<And>x. x \<in> S \<Longrightarrow> h x \<in> T \<and> k (h x) = x \<and> g (h x) = f x"
- shows "setsum f S = setsum g T"
- using kh hk by (fact setsum.eq_general_reverses)
-
-
-subsubsection {* Properties in more restricted classes of structures *}
-
-lemma setsum_Un: "finite A ==> finite B ==>
- (setsum f (A Un B) :: 'a :: ab_group_add) =
- setsum f A + setsum f B - setsum f (A Int B)"
-by (subst setsum_Un_Int [symmetric], auto simp add: algebra_simps)
-
-lemma setsum_Un2:
- assumes "finite (A \<union> B)"
- shows "setsum f (A \<union> B) = setsum f (A - B) + setsum f (B - A) + setsum f (A \<inter> B)"
-proof -
- have "A \<union> B = A - B \<union> (B - A) \<union> A \<inter> B"
- by auto
- with assms show ?thesis by simp (subst setsum_Un_disjoint, auto)+
-qed
-
-lemma setsum_diff1: "finite A \<Longrightarrow>
- (setsum f (A - {a}) :: ('a::ab_group_add)) =
- (if a:A then setsum f A - f a else setsum f A)"
-by (erule finite_induct) (auto simp add: insert_Diff_if)
-
-lemma setsum_diff:
- assumes le: "finite A" "B \<subseteq> A"
- shows "setsum f (A - B) = setsum f A - ((setsum f B)::('a::ab_group_add))"
-proof -
- from le have finiteB: "finite B" using finite_subset by auto
- show ?thesis using finiteB le
- proof induct
- case empty
- thus ?case by auto
- next
- case (insert x F)
- thus ?case using le finiteB
- by (simp add: Diff_insert[where a=x and B=F] setsum_diff1 insert_absorb)
- qed
-qed
-
-lemma setsum_mono:
- assumes le: "\<And>i. i\<in>K \<Longrightarrow> f (i::'a) \<le> ((g i)::('b::{comm_monoid_add, ordered_ab_semigroup_add}))"
- shows "(\<Sum>i\<in>K. f i) \<le> (\<Sum>i\<in>K. g i)"
-proof (cases "finite K")
- case True
- thus ?thesis using le
- proof induct
- case empty
- thus ?case by simp
- next
- case insert
- thus ?case using add_mono by fastforce
- qed
-next
- case False then show ?thesis by simp
-qed
-
-lemma setsum_strict_mono:
- fixes f :: "'a \<Rightarrow> 'b::{ordered_cancel_ab_semigroup_add,comm_monoid_add}"
- assumes "finite A" "A \<noteq> {}"
- and "!!x. x:A \<Longrightarrow> f x < g x"
- shows "setsum f A < setsum g A"
- using assms
-proof (induct rule: finite_ne_induct)
- case singleton thus ?case by simp
-next
- case insert thus ?case by (auto simp: add_strict_mono)
-qed
-
-lemma setsum_strict_mono_ex1:
-fixes f :: "'a \<Rightarrow> 'b::{comm_monoid_add, ordered_cancel_ab_semigroup_add}"
-assumes "finite A" and "ALL x:A. f x \<le> g x" and "EX a:A. f a < g a"
-shows "setsum f A < setsum g A"
-proof-
- from assms(3) obtain a where a: "a:A" "f a < g a" by blast
- have "setsum f A = setsum f ((A-{a}) \<union> {a})"
- by(simp add:insert_absorb[OF `a:A`])
- also have "\<dots> = setsum f (A-{a}) + setsum f {a}"
- using `finite A` by(subst setsum_Un_disjoint) auto
- also have "setsum f (A-{a}) \<le> setsum g (A-{a})"
- by(rule setsum_mono)(simp add: assms(2))
- also have "setsum f {a} < setsum g {a}" using a by simp
- also have "setsum g (A - {a}) + setsum g {a} = setsum g((A-{a}) \<union> {a})"
- using `finite A` by(subst setsum_Un_disjoint[symmetric]) auto
- also have "\<dots> = setsum g A" by(simp add:insert_absorb[OF `a:A`])
- finally show ?thesis by (metis add_right_mono add_strict_left_mono)
-qed
-
-lemma setsum_negf:
- "setsum (%x. - (f x)::'a::ab_group_add) A = - setsum f A"
-proof (cases "finite A")
- case True thus ?thesis by (induct set: finite) auto
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_subtractf:
- "setsum (%x. ((f x)::'a::ab_group_add) - g x) A =
- setsum f A - setsum g A"
- using setsum_addf [of f "- g" A] by (simp add: setsum_negf)
-
-lemma setsum_nonneg:
- assumes nn: "\<forall>x\<in>A. (0::'a::{ordered_ab_semigroup_add,comm_monoid_add}) \<le> f x"
- shows "0 \<le> setsum f A"
-proof (cases "finite A")
- case True thus ?thesis using nn
- proof induct
- case empty then show ?case by simp
- next
- case (insert x F)
- then have "0 + 0 \<le> f x + setsum f F" by (blast intro: add_mono)
- with insert show ?case by simp
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_nonpos:
- assumes np: "\<forall>x\<in>A. f x \<le> (0::'a::{ordered_ab_semigroup_add,comm_monoid_add})"
- shows "setsum f A \<le> 0"
-proof (cases "finite A")
- case True thus ?thesis using np
- proof induct
- case empty then show ?case by simp
- next
- case (insert x F)
- then have "f x + setsum f F \<le> 0 + 0" by (blast intro: add_mono)
- with insert show ?case by simp
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_nonneg_leq_bound:
- fixes f :: "'a \<Rightarrow> 'b::{ordered_ab_group_add}"
- assumes "finite s" "\<And>i. i \<in> s \<Longrightarrow> f i \<ge> 0" "(\<Sum>i \<in> s. f i) = B" "i \<in> s"
- shows "f i \<le> B"
-proof -
- have "0 \<le> (\<Sum> i \<in> s - {i}. f i)" and "0 \<le> f i"
- using assms by (auto intro!: setsum_nonneg)
- moreover
- have "(\<Sum> i \<in> s - {i}. f i) + f i = B"
- using assms by (simp add: setsum_diff1)
- ultimately show ?thesis by auto
-qed
-
-lemma setsum_nonneg_0:
- fixes f :: "'a \<Rightarrow> 'b::{ordered_ab_group_add}"
- assumes "finite s" and pos: "\<And> i. i \<in> s \<Longrightarrow> f i \<ge> 0"
- and "(\<Sum> i \<in> s. f i) = 0" and i: "i \<in> s"
- shows "f i = 0"
- using setsum_nonneg_leq_bound[OF assms] pos[OF i] by auto
-
-lemma setsum_mono2:
-fixes f :: "'a \<Rightarrow> 'b :: ordered_comm_monoid_add"
-assumes fin: "finite B" and sub: "A \<subseteq> B" and nn: "\<And>b. b \<in> B-A \<Longrightarrow> 0 \<le> f b"
-shows "setsum f A \<le> setsum f B"
-proof -
- have "setsum f A \<le> setsum f A + setsum f (B-A)"
- by(simp add: add_increasing2[OF setsum_nonneg] nn Ball_def)
- also have "\<dots> = setsum f (A \<union> (B-A))" using fin finite_subset[OF sub fin]
- by (simp add:setsum_Un_disjoint del:Un_Diff_cancel)
- also have "A \<union> (B-A) = B" using sub by blast
- finally show ?thesis .
-qed
-
-lemma setsum_mono3: "finite B ==> A <= B ==>
- ALL x: B - A.
- 0 <= ((f x)::'a::{comm_monoid_add,ordered_ab_semigroup_add}) ==>
- setsum f A <= setsum f B"
- apply (subgoal_tac "setsum f B = setsum f A + setsum f (B - A)")
- apply (erule ssubst)
- apply (subgoal_tac "setsum f A + 0 <= setsum f A + setsum f (B - A)")
- apply simp
- apply (rule add_left_mono)
- apply (erule setsum_nonneg)
- apply (subst setsum_Un_disjoint [THEN sym])
- apply (erule finite_subset, assumption)
- apply (rule finite_subset)
- prefer 2
- apply assumption
- apply (auto simp add: sup_absorb2)
-done
-
-lemma setsum_right_distrib:
- fixes f :: "'a => ('b::semiring_0)"
- shows "r * setsum f A = setsum (%n. r * f n) A"
-proof (cases "finite A")
- case True
- thus ?thesis
- proof induct
- case empty thus ?case by simp
- next
- case (insert x A) thus ?case by (simp add: distrib_left)
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_left_distrib:
- "setsum f A * (r::'a::semiring_0) = (\<Sum>n\<in>A. f n * r)"
-proof (cases "finite A")
- case True
- then show ?thesis
- proof induct
- case empty thus ?case by simp
- next
- case (insert x A) thus ?case by (simp add: distrib_right)
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_divide_distrib:
- "setsum f A / (r::'a::field) = (\<Sum>n\<in>A. f n / r)"
-proof (cases "finite A")
- case True
- then show ?thesis
- proof induct
- case empty thus ?case by simp
- next
- case (insert x A) thus ?case by (simp add: add_divide_distrib)
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_abs[iff]:
- fixes f :: "'a => ('b::ordered_ab_group_add_abs)"
- shows "abs (setsum f A) \<le> setsum (%i. abs(f i)) A"
-proof (cases "finite A")
- case True
- thus ?thesis
- proof induct
- case empty thus ?case by simp
- next
- case (insert x A)
- thus ?case by (auto intro: abs_triangle_ineq order_trans)
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_abs_ge_zero[iff]:
- fixes f :: "'a => ('b::ordered_ab_group_add_abs)"
- shows "0 \<le> setsum (%i. abs(f i)) A"
-proof (cases "finite A")
- case True
- thus ?thesis
- proof induct
- case empty thus ?case by simp
- next
- case (insert x A) thus ?case by auto
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma abs_setsum_abs[simp]:
- fixes f :: "'a => ('b::ordered_ab_group_add_abs)"
- shows "abs (\<Sum>a\<in>A. abs(f a)) = (\<Sum>a\<in>A. abs(f a))"
-proof (cases "finite A")
- case True
- thus ?thesis
- proof induct
- case empty thus ?case by simp
- next
- case (insert a A)
- hence "\<bar>\<Sum>a\<in>insert a A. \<bar>f a\<bar>\<bar> = \<bar>\<bar>f a\<bar> + (\<Sum>a\<in>A. \<bar>f a\<bar>)\<bar>" by simp
- also have "\<dots> = \<bar>\<bar>f a\<bar> + \<bar>\<Sum>a\<in>A. \<bar>f a\<bar>\<bar>\<bar>" using insert by simp
- also have "\<dots> = \<bar>f a\<bar> + \<bar>\<Sum>a\<in>A. \<bar>f a\<bar>\<bar>"
- by (simp del: abs_of_nonneg)
- also have "\<dots> = (\<Sum>a\<in>insert a A. \<bar>f a\<bar>)" using insert by simp
- finally show ?case .
- qed
-next
- case False thus ?thesis by simp
-qed
-
-lemma setsum_diff1'[rule_format]:
- "finite A \<Longrightarrow> a \<in> A \<longrightarrow> (\<Sum> x \<in> A. f x) = f a + (\<Sum> x \<in> (A - {a}). f x)"
-apply (erule finite_induct[where F=A and P="% A. (a \<in> A \<longrightarrow> (\<Sum> x \<in> A. f x) = f a + (\<Sum> x \<in> (A - {a}). f x))"])
-apply (auto simp add: insert_Diff_if add_ac)
-done
-
-lemma setsum_diff1_ring: assumes "finite A" "a \<in> A"
- shows "setsum f (A - {a}) = setsum f A - (f a::'a::ring)"
-unfolding setsum_diff1'[OF assms] by auto
-
-lemma setsum_product:
- fixes f :: "'a => ('b::semiring_0)"
- shows "setsum f A * setsum g B = (\<Sum>i\<in>A. \<Sum>j\<in>B. f i * g j)"
- by (simp add: setsum_right_distrib setsum_left_distrib) (rule setsum_commute)
-
-lemma setsum_mult_setsum_if_inj:
-fixes f :: "'a => ('b::semiring_0)"
-shows "inj_on (%(a,b). f a * g b) (A \<times> B) ==>
- setsum f A * setsum g B = setsum id {f a * g b|a b. a:A & b:B}"
-by(auto simp: setsum_product setsum_cartesian_product
- intro!: setsum_reindex_cong[symmetric])
-
-lemma setsum_SucD: "setsum f A = Suc n ==> EX a:A. 0 < f a"
-apply (case_tac "finite A")
- prefer 2 apply simp
-apply (erule rev_mp)
-apply (erule finite_induct, auto)
-done
-
-lemma setsum_eq_0_iff [simp]:
- "finite F ==> (setsum f F = 0) = (ALL a:F. f a = (0::nat))"
- by (induct set: finite) auto
-
-lemma setsum_eq_Suc0_iff: "finite A \<Longrightarrow>
- setsum f A = Suc 0 \<longleftrightarrow> (EX a:A. f a = Suc 0 & (ALL b:A. a\<noteq>b \<longrightarrow> f b = 0))"
-apply(erule finite_induct)
-apply (auto simp add:add_is_1)
-done
-
-lemmas setsum_eq_1_iff = setsum_eq_Suc0_iff[simplified One_nat_def[symmetric]]
-
-lemma setsum_Un_nat: "finite A ==> finite B ==>
- (setsum f (A Un B) :: nat) = setsum f A + setsum f B - setsum f (A Int B)"
- -- {* For the natural numbers, we have subtraction. *}
-by (subst setsum_Un_Int [symmetric], auto simp add: algebra_simps)
-
-lemma setsum_diff1_nat: "(setsum f (A - {a}) :: nat) =
- (if a:A then setsum f A - f a else setsum f A)"
-apply (case_tac "finite A")
- prefer 2 apply simp
-apply (erule finite_induct)
- apply (auto simp add: insert_Diff_if)
-apply (drule_tac a = a in mk_disjoint_insert, auto)
-done
-
-lemma setsum_diff_nat:
-assumes "finite B" and "B \<subseteq> A"
-shows "(setsum f (A - B) :: nat) = (setsum f A) - (setsum f B)"
-using assms
-proof induct
- show "setsum f (A - {}) = (setsum f A) - (setsum f {})" by simp
-next
- fix F x assume finF: "finite F" and xnotinF: "x \<notin> F"
- and xFinA: "insert x F \<subseteq> A"
- and IH: "F \<subseteq> A \<Longrightarrow> setsum f (A - F) = setsum f A - setsum f F"
- from xnotinF xFinA have xinAF: "x \<in> (A - F)" by simp
- from xinAF have A: "setsum f ((A - F) - {x}) = setsum f (A - F) - f x"
- by (simp add: setsum_diff1_nat)
- from xFinA have "F \<subseteq> A" by simp
- with IH have "setsum f (A - F) = setsum f A - setsum f F" by simp
- with A have B: "setsum f ((A - F) - {x}) = setsum f A - setsum f F - f x"
- by simp
- from xnotinF have "A - insert x F = (A - F) - {x}" by auto
- with B have C: "setsum f (A - insert x F) = setsum f A - setsum f F - f x"
- by simp
- from finF xnotinF have "setsum f (insert x F) = setsum f F + f x" by simp
- with C have "setsum f (A - insert x F) = setsum f A - setsum f (insert x F)"
- by simp
- thus "setsum f (A - insert x F) = setsum f A - setsum f (insert x F)" by simp
-qed
-
-lemma setsum_comp_morphism:
- assumes "h 0 = 0" and "\<And>x y. h (x + y) = h x + h y"
- shows "setsum (h \<circ> g) A = h (setsum g A)"
-proof (cases "finite A")
- case False then show ?thesis by (simp add: assms)
-next
- case True then show ?thesis by (induct A) (simp_all add: assms)
-qed
-
-
-subsubsection {* Cardinality as special case of @{const setsum} *}
-
-lemma card_eq_setsum:
- "card A = setsum (\<lambda>x. 1) A"
-proof -
- have "plus \<circ> (\<lambda>_. Suc 0) = (\<lambda>_. Suc)"
- by (simp add: fun_eq_iff)
- then have "Finite_Set.fold (plus \<circ> (\<lambda>_. Suc 0)) = Finite_Set.fold (\<lambda>_. Suc)"
- by (rule arg_cong)
- then have "Finite_Set.fold (plus \<circ> (\<lambda>_. Suc 0)) 0 A = Finite_Set.fold (\<lambda>_. Suc) 0 A"
- by (blast intro: fun_cong)
- then show ?thesis by (simp add: card.eq_fold setsum.eq_fold)
-qed
-
-lemma setsum_constant [simp]:
- "(\<Sum>x \<in> A. y) = of_nat (card A) * y"
-apply (cases "finite A")
-apply (erule finite_induct)
-apply (auto simp add: algebra_simps)
-done
-
-lemma setsum_bounded:
- assumes le: "\<And>i. i\<in>A \<Longrightarrow> f i \<le> (K::'a::{semiring_1, ordered_ab_semigroup_add})"
- shows "setsum f A \<le> of_nat (card A) * K"
-proof (cases "finite A")
- case True
- thus ?thesis using le setsum_mono[where K=A and g = "%x. K"] by simp
-next
- case False thus ?thesis by simp
-qed
-
-lemma card_UN_disjoint:
- assumes "finite I" and "\<forall>i\<in>I. finite (A i)"
- and "\<forall>i\<in>I. \<forall>j\<in>I. i \<noteq> j \<longrightarrow> A i \<inter> A j = {}"
- shows "card (UNION I A) = (\<Sum>i\<in>I. card(A i))"
-proof -
- have "(\<Sum>i\<in>I. card (A i)) = (\<Sum>i\<in>I. \<Sum>x\<in>A i. 1)" by simp
- with assms show ?thesis by (simp add: card_eq_setsum setsum_UN_disjoint del: setsum_constant)
-qed
-
-lemma card_Union_disjoint:
- "finite C ==> (ALL A:C. finite A) ==>
- (ALL A:C. ALL B:C. A \<noteq> B --> A Int B = {})
- ==> card (Union C) = setsum card C"
-apply (frule card_UN_disjoint [of C id])
-apply (simp_all add: SUP_def id_def)
-done
-
-
-subsubsection {* Cardinality of products *}
-
-lemma card_SigmaI [simp]:
- "\<lbrakk> finite A; ALL a:A. finite (B a) \<rbrakk>
- \<Longrightarrow> card (SIGMA x: A. B x) = (\<Sum>a\<in>A. card (B a))"
-by(simp add: card_eq_setsum setsum_Sigma del:setsum_constant)
-
-(*
-lemma SigmaI_insert: "y \<notin> A ==>
- (SIGMA x:(insert y A). B x) = (({y} <*> (B y)) \<union> (SIGMA x: A. B x))"
- by auto
-*)
-
-lemma card_cartesian_product: "card (A <*> B) = card(A) * card(B)"
- by (cases "finite A \<and> finite B")
- (auto simp add: card_eq_0_iff dest: finite_cartesian_productD1 finite_cartesian_productD2)
-
-lemma card_cartesian_product_singleton: "card({x} <*> A) = card(A)"
-by (simp add: card_cartesian_product)
-
-
-subsection {* Generalized product over a set *}
-
-context comm_monoid_mult
-begin
-
-definition setprod :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'a"
-where
- "setprod = comm_monoid_set.F times 1"
-
-sublocale setprod!: comm_monoid_set times 1
-where
- "comm_monoid_set.F times 1 = setprod"
-proof -
- show "comm_monoid_set times 1" ..
- then interpret setprod!: comm_monoid_set times 1 .
- from setprod_def show "comm_monoid_set.F times 1 = setprod" by rule
-qed
-
-abbreviation
- Setprod ("\<Prod>_" [1000] 999) where
- "\<Prod>A \<equiv> setprod (\<lambda>x. x) A"
-
-end
-
-syntax
- "_setprod" :: "pttrn => 'a set => 'b => 'b::comm_monoid_mult" ("(3PROD _:_. _)" [0, 51, 10] 10)
-syntax (xsymbols)
- "_setprod" :: "pttrn => 'a set => 'b => 'b::comm_monoid_mult" ("(3\<Prod>_\<in>_. _)" [0, 51, 10] 10)
-syntax (HTML output)
- "_setprod" :: "pttrn => 'a set => 'b => 'b::comm_monoid_mult" ("(3\<Prod>_\<in>_. _)" [0, 51, 10] 10)
-
-translations -- {* Beware of argument permutation! *}
- "PROD i:A. b" == "CONST setprod (%i. b) A"
- "\<Prod>i\<in>A. b" == "CONST setprod (%i. b) A"
-
-text{* Instead of @{term"\<Prod>x\<in>{x. P}. e"} we introduce the shorter
- @{text"\<Prod>x|P. e"}. *}
-
-syntax
- "_qsetprod" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3PROD _ |/ _./ _)" [0,0,10] 10)
-syntax (xsymbols)
- "_qsetprod" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Prod>_ | (_)./ _)" [0,0,10] 10)
-syntax (HTML output)
- "_qsetprod" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Prod>_ | (_)./ _)" [0,0,10] 10)
-
-translations
- "PROD x|P. t" => "CONST setprod (%x. t) {x. P}"
- "\<Prod>x|P. t" => "CONST setprod (%x. t) {x. P}"
-
-text {* TODO These are candidates for generalization *}
-
-context comm_monoid_mult
-begin
-
-lemma setprod_reindex_id:
- "inj_on f B ==> setprod f B = setprod id (f ` B)"
- by (auto simp add: setprod.reindex)
-
-lemma setprod_reindex_cong:
- "inj_on f A ==> B = f ` A ==> g = h \<circ> f ==> setprod h B = setprod g A"
- by (frule setprod.reindex, simp)
-
-lemma strong_setprod_reindex_cong:
- assumes i: "inj_on f A"
- and B: "B = f ` A" and eq: "\<And>x. x \<in> A \<Longrightarrow> g x = (h \<circ> f) x"
- shows "setprod h B = setprod g A"
-proof-
- have "setprod h B = setprod (h o f) A"
- by (simp add: B setprod.reindex [OF i, of h])
- then show ?thesis apply simp
- apply (rule setprod.cong)
- apply simp
- by (simp add: eq)
-qed
-
-lemma setprod_Union_disjoint:
- assumes "\<forall>A\<in>C. finite A" "\<forall>A\<in>C. \<forall>B\<in>C. A \<noteq> B \<longrightarrow> A Int B = {}"
- shows "setprod f (Union C) = setprod (setprod f) C"
- using assms by (fact setprod.Union_disjoint)
-
-text{*Here we can eliminate the finiteness assumptions, by cases.*}
-lemma setprod_cartesian_product:
- "(\<Prod>x\<in>A. (\<Prod>y\<in> B. f x y)) = (\<Prod>(x,y)\<in>(A <*> B). f x y)"
- by (fact setprod.cartesian_product)
-
-lemma setprod_Un2:
- assumes "finite (A \<union> B)"
- shows "setprod f (A \<union> B) = setprod f (A - B) * setprod f (B - A) * setprod f (A \<inter> B)"
-proof -
- have "A \<union> B = A - B \<union> (B - A) \<union> A \<inter> B"
- by auto
- with assms show ?thesis by simp (subst setprod.union_disjoint, auto)+
-qed
-
-end
-
-text {* TODO These are legacy *}
-
-lemma setprod_empty: "setprod f {} = 1"
- by (fact setprod.empty)
-
-lemma setprod_insert: "[| finite A; a \<notin> A |] ==>
- setprod f (insert a A) = f a * setprod f A"
- by (fact setprod.insert)
-
-lemma setprod_infinite: "~ finite A ==> setprod f A = 1"
- by (fact setprod.infinite)
-
-lemma setprod_reindex:
- "inj_on f B ==> setprod h (f ` B) = setprod (h \<circ> f) B"
- by (fact setprod.reindex)
-
-lemma setprod_cong:
- "A = B ==> (!!x. x:B ==> f x = g x) ==> setprod f A = setprod g B"
- by (fact setprod.cong)
-
-lemma strong_setprod_cong:
- "A = B ==> (!!x. x:B =simp=> f x = g x) ==> setprod f A = setprod g B"
- by (fact setprod.strong_cong)
-
-lemma setprod_Un_one:
- "\<lbrakk> finite S; finite T; \<forall>x \<in> S\<inter>T. f x = 1 \<rbrakk>
- \<Longrightarrow> setprod f (S \<union> T) = setprod f S * setprod f T"
- by (fact setprod.union_inter_neutral)
-
-lemmas setprod_1 = setprod.neutral_const
-lemmas setprod_1' = setprod.neutral
-
-lemma setprod_Un_Int: "finite A ==> finite B
- ==> setprod g (A Un B) * setprod g (A Int B) = setprod g A * setprod g B"
- by (fact setprod.union_inter)
-
-lemma setprod_Un_disjoint: "finite A ==> finite B
- ==> A Int B = {} ==> setprod g (A Un B) = setprod g A * setprod g B"
- by (fact setprod.union_disjoint)
-
-lemma setprod_subset_diff: "\<lbrakk> B \<subseteq> A; finite A \<rbrakk> \<Longrightarrow>
- setprod f A = setprod f (A - B) * setprod f B"
- by (fact setprod.subset_diff)
-
-lemma setprod_mono_one_left:
- "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. f i = 1 \<rbrakk> \<Longrightarrow> setprod f S = setprod f T"
- by (fact setprod.mono_neutral_left)
-
-lemmas setprod_mono_one_right = setprod.mono_neutral_right
-
-lemma setprod_mono_one_cong_left:
- "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1; \<And>x. x \<in> S \<Longrightarrow> f x = g x \<rbrakk>
- \<Longrightarrow> setprod f S = setprod g T"
- by (fact setprod.mono_neutral_cong_left)
-
-lemmas setprod_mono_one_cong_right = setprod.mono_neutral_cong_right
-
-lemma setprod_delta: "finite S \<Longrightarrow>
- setprod (\<lambda>k. if k=a then b k else 1) S = (if a \<in> S then b a else 1)"
- by (fact setprod.delta)
-
-lemma setprod_delta': "finite S \<Longrightarrow>
- setprod (\<lambda>k. if a = k then b k else 1) S = (if a\<in> S then b a else 1)"
- by (fact setprod.delta')
-
-lemma setprod_UN_disjoint:
- "finite I ==> (ALL i:I. finite (A i)) ==>
- (ALL i:I. ALL j:I. i \<noteq> j --> A i Int A j = {}) ==>
- setprod f (UNION I A) = setprod (%i. setprod f (A i)) I"
- by (fact setprod.UNION_disjoint)
-
-lemma setprod_Sigma: "finite A ==> ALL x:A. finite (B x) ==>
- (\<Prod>x\<in>A. (\<Prod>y\<in> B x. f x y)) =
- (\<Prod>(x,y)\<in>(SIGMA x:A. B x). f x y)"
- by (fact setprod.Sigma)
-
-lemma setprod_timesf: "setprod (\<lambda>x. f x * g x) A = setprod f A * setprod g A"
- by (fact setprod.distrib)
-
-
-subsubsection {* Properties in more restricted classes of structures *}
-
-lemma setprod_zero:
- "finite A ==> EX x: A. f x = (0::'a::comm_semiring_1) ==> setprod f A = 0"
-apply (induct set: finite, force, clarsimp)
-apply (erule disjE, auto)
-done
-
-lemma setprod_zero_iff[simp]: "finite A ==>
- (setprod f A = (0::'a::{comm_semiring_1,no_zero_divisors})) =
- (EX x: A. f x = 0)"
-by (erule finite_induct, auto simp:no_zero_divisors)
-
-lemma setprod_Un: "finite A ==> finite B ==> (ALL x: A Int B. f x \<noteq> 0) ==>
- (setprod f (A Un B) :: 'a ::{field})
- = setprod f A * setprod f B / setprod f (A Int B)"
-by (subst setprod_Un_Int [symmetric], auto)
-
-lemma setprod_nonneg [rule_format]:
- "(ALL x: A. (0::'a::linordered_semidom) \<le> f x) --> 0 \<le> setprod f A"
-by (cases "finite A", induct set: finite, simp_all add: mult_nonneg_nonneg)
-
-lemma setprod_pos [rule_format]: "(ALL x: A. (0::'a::linordered_semidom) < f x)
- --> 0 < setprod f A"
-by (cases "finite A", induct set: finite, simp_all add: mult_pos_pos)
-
-lemma setprod_diff1: "finite A ==> f a \<noteq> 0 ==>
- (setprod f (A - {a}) :: 'a :: {field}) =
- (if a:A then setprod f A / f a else setprod f A)"
- by (erule finite_induct) (auto simp add: insert_Diff_if)
-
-lemma setprod_inversef:
- fixes f :: "'b \<Rightarrow> 'a::field_inverse_zero"
- shows "finite A ==> setprod (inverse \<circ> f) A = inverse (setprod f A)"
-by (erule finite_induct) auto
-
-lemma setprod_dividef:
- fixes f :: "'b \<Rightarrow> 'a::field_inverse_zero"
- shows "finite A
- ==> setprod (%x. f x / g x) A = setprod f A / setprod g A"
-apply (subgoal_tac
- "setprod (%x. f x / g x) A = setprod (%x. f x * (inverse \<circ> g) x) A")
-apply (erule ssubst)
-apply (subst divide_inverse)
-apply (subst setprod_timesf)
-apply (subst setprod_inversef, assumption+, rule refl)
-apply (rule setprod_cong, rule refl)
-apply (subst divide_inverse, auto)
-done
-
-lemma setprod_dvd_setprod [rule_format]:
- "(ALL x : A. f x dvd g x) \<longrightarrow> setprod f A dvd setprod g A"
- apply (cases "finite A")
- apply (induct set: finite)
- apply (auto simp add: dvd_def)
- apply (rule_tac x = "k * ka" in exI)
- apply (simp add: algebra_simps)
-done
-
-lemma setprod_dvd_setprod_subset:
- "finite B \<Longrightarrow> A <= B \<Longrightarrow> setprod f A dvd setprod f B"
- apply (subgoal_tac "setprod f B = setprod f A * setprod f (B - A)")
- apply (unfold dvd_def, blast)
- apply (subst setprod_Un_disjoint [symmetric])
- apply (auto elim: finite_subset intro: setprod_cong)
-done
-
-lemma setprod_dvd_setprod_subset2:
- "finite B \<Longrightarrow> A <= B \<Longrightarrow> ALL x : A. (f x::'a::comm_semiring_1) dvd g x \<Longrightarrow>
- setprod f A dvd setprod g B"
- apply (rule dvd_trans)
- apply (rule setprod_dvd_setprod, erule (1) bspec)
- apply (erule (1) setprod_dvd_setprod_subset)
-done
-
-lemma dvd_setprod: "finite A \<Longrightarrow> i:A \<Longrightarrow>
- (f i ::'a::comm_semiring_1) dvd setprod f A"
-by (induct set: finite) (auto intro: dvd_mult)
-
-lemma dvd_setsum [rule_format]: "(ALL i : A. d dvd f i) \<longrightarrow>
- (d::'a::comm_semiring_1) dvd (SUM x : A. f x)"
- apply (cases "finite A")
- apply (induct set: finite)
- apply auto
-done
-
-lemma setprod_mono:
- fixes f :: "'a \<Rightarrow> 'b\<Colon>linordered_semidom"
- assumes "\<forall>i\<in>A. 0 \<le> f i \<and> f i \<le> g i"
- shows "setprod f A \<le> setprod g A"
-proof (cases "finite A")
- case True
- hence ?thesis "setprod f A \<ge> 0" using subset_refl[of A]
- proof (induct A rule: finite_subset_induct)
- case (insert a F)
- thus "setprod f (insert a F) \<le> setprod g (insert a F)" "0 \<le> setprod f (insert a F)"
- unfolding setprod_insert[OF insert(1,3)]
- using assms[rule_format,OF insert(2)] insert
- by (auto intro: mult_mono mult_nonneg_nonneg)
- qed auto
- thus ?thesis by simp
-qed auto
-
-lemma abs_setprod:
- fixes f :: "'a \<Rightarrow> 'b\<Colon>{linordered_field,abs}"
- shows "abs (setprod f A) = setprod (\<lambda>x. abs (f x)) A"
-proof (cases "finite A")
- case True thus ?thesis
- by induct (auto simp add: field_simps abs_mult)
-qed auto
-
-lemma setprod_constant: "finite A ==> (\<Prod>x\<in> A. (y::'a::{comm_monoid_mult})) = y^(card A)"
-apply (erule finite_induct)
-apply auto
-done
-
-lemma setprod_gen_delta:
- assumes fS: "finite S"
- shows "setprod (\<lambda>k. if k=a then b k else c) S = (if a \<in> S then (b a ::'a::comm_monoid_mult) * c^ (card S - 1) else c^ card S)"
-proof-
- let ?f = "(\<lambda>k. if k=a then b k else c)"
- {assume a: "a \<notin> S"
- hence "\<forall> k\<in> S. ?f k = c" by simp
- hence ?thesis using a setprod_constant[OF fS, of c] by simp }
- moreover
- {assume a: "a \<in> S"
- let ?A = "S - {a}"
- let ?B = "{a}"
- have eq: "S = ?A \<union> ?B" using a by blast
- have dj: "?A \<inter> ?B = {}" by simp
- from fS have fAB: "finite ?A" "finite ?B" by auto
- have fA0:"setprod ?f ?A = setprod (\<lambda>i. c) ?A"
- apply (rule setprod_cong) by auto
- have cA: "card ?A = card S - 1" using fS a by auto
- have fA1: "setprod ?f ?A = c ^ card ?A" unfolding fA0 apply (rule setprod_constant) using fS by auto
- have "setprod ?f ?A * setprod ?f ?B = setprod ?f S"
- using setprod_Un_disjoint[OF fAB dj, of ?f, unfolded eq[symmetric]]
- by simp
- then have ?thesis using a cA
- by (simp add: fA1 field_simps cong add: setprod_cong cong del: if_weak_cong)}
- ultimately show ?thesis by blast
-qed
-
-lemma setprod_eq_1_iff [simp]:
- "finite F ==> setprod f F = 1 \<longleftrightarrow> (ALL a:F. f a = (1::nat))"
- by (induct set: finite) auto
-
-lemma setprod_pos_nat:
- "finite S ==> (ALL x : S. f x > (0::nat)) ==> setprod f S > 0"
-using setprod_zero_iff by(simp del:neq0_conv add:neq0_conv[symmetric])
-
-lemma setprod_pos_nat_iff[simp]:
- "finite S ==> (setprod f S > 0) = (ALL x : S. f x > (0::nat))"
-using setprod_zero_iff by(simp del:neq0_conv add:neq0_conv[symmetric])
-
-
-subsection {* Generic lattice operations over a set *}
-
-no_notation times (infixl "*" 70)
-no_notation Groups.one ("1")
-
-
-subsubsection {* Without neutral element *}
-
-locale semilattice_set = semilattice
-begin
-
-interpretation comp_fun_idem f
- by default (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 default (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 * F A"
-proof -
- from `A \<noteq> {}` 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 `finite A` and `x \<notin> A`
- have "finite (insert x B)" and "b \<notin> insert x B" by auto
- then have "F (insert b (insert x B)) = x * 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 * F A = F A"
-proof -
- from assms have "A \<noteq> {}" by auto
- with `finite A` show ?thesis using `x \<in> A`
- 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 * 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 * 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 * 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 * 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 * 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 * y \<in> {x, y}"
- shows "F A \<in> A"
-using `finite A` `A \<noteq> {}` 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 * y) = h x * 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 * F N)" by simp
- also have "\<dots> = h n * h (F N)" by (rule hom)
- also have "h (F N) = F (h ` N)" by (rule insert)
- also have "h n * \<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
-
-end
-
-locale semilattice_order_set = semilattice_order + semilattice_set
-begin
-
-lemma bounded_iff:
- assumes "finite A" and "A \<noteq> {}"
- shows "x \<preceq> F A \<longleftrightarrow> (\<forall>a\<in>A. x \<preceq> a)"
- using assms by (induct rule: finite_ne_induct) (simp_all add: bounded_iff)
-
-lemma boundedI:
- assumes "finite A"
- assumes "A \<noteq> {}"
- assumes "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
- shows "x \<preceq> F A"
- using assms by (simp add: bounded_iff)
-
-lemma boundedE:
- assumes "finite A" and "A \<noteq> {}" and "x \<preceq> F A"
- obtains "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
- using assms by (simp add: bounded_iff)
-
-lemma coboundedI:
- assumes "finite A"
- and "a \<in> A"
- shows "F A \<preceq> a"
-proof -
- from assms have "A \<noteq> {}" by auto
- from `finite A` `A \<noteq> {}` `a \<in> A` 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 antimono:
- assumes "A \<subseteq> B" and "A \<noteq> {}" and "finite B"
- shows "F B \<preceq> 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 `A \<subseteq> B` by blast
- then have "F B = F (A \<union> (B - A))" by simp
- also have "\<dots> = F A * F (B - A)" using False assms by (subst union) (auto intro: finite_subset)
- also have "\<dots> \<preceq> F A" by simp
- finally show ?thesis .
-qed
-
-end
-
-
-subsubsection {* With neutral element *}
-
-locale semilattice_neutr_set = semilattice_neutr
-begin
-
-interpretation comp_fun_idem f
- by default (simp_all add: fun_eq_iff left_commute)
-
-definition F :: "'a set \<Rightarrow> 'a"
-where
- eq_fold: "F A = Finite_Set.fold f 1 A"
-
-lemma infinite [simp]:
- "\<not> finite A \<Longrightarrow> F A = 1"
- by (simp add: eq_fold)
-
-lemma empty [simp]:
- "F {} = 1"
- by (simp add: eq_fold)
-
-lemma insert [simp]:
- assumes "finite A"
- shows "F (insert x A) = x * F A"
- using assms by (simp add: eq_fold)
-
-lemma in_idem:
- assumes "finite A" and "x \<in> A"
- shows "x * F A = F A"
-proof -
- from assms have "A \<noteq> {}" by auto
- with `finite A` show ?thesis using `x \<in> A`
- 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 * 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 * 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 * 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 * 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 * y \<in> {x, y}"
- shows "F A \<in> A"
-using `finite A` `A \<noteq> {}` 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 = semilattice_neutr_order + semilattice_neutr_set
-begin
-
-lemma bounded_iff:
- assumes "finite A"
- shows "x \<preceq> F A \<longleftrightarrow> (\<forall>a\<in>A. x \<preceq> a)"
- using assms by (induct A) (simp_all add: bounded_iff)
-
-lemma boundedI:
- assumes "finite A"
- assumes "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
- shows "x \<preceq> F A"
- using assms by (simp add: bounded_iff)
-
-lemma boundedE:
- assumes "finite A" and "x \<preceq> F A"
- obtains "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
- using assms by (simp add: bounded_iff)
-
-lemma coboundedI:
- assumes "finite A"
- and "a \<in> A"
- shows "F A \<preceq> a"
-proof -
- from assms have "A \<noteq> {}" by auto
- from `finite A` `A \<noteq> {}` `a \<in> A` 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 antimono:
- assumes "A \<subseteq> B" and "finite B"
- shows "F B \<preceq> 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 `A \<subseteq> B` by blast
- then have "F B = F (A \<union> (B - A))" by simp
- also have "\<dots> = F A * F (B - A)" using False assms by (subst union) (auto intro: finite_subset)
- also have "\<dots> \<preceq> F A" by simp
- finally show ?thesis .
-qed
-
-end
-
-notation times (infixl "*" 70)
-notation Groups.one ("1")
-
-
-subsection {* Lattice operations on finite sets *}
-
-text {*
- For historic reasons, there is the sublocale dependency from @{class distrib_lattice}
- to @{class linorder}. This is badly designed: both should depend on a common abstract
- distributive lattice rather than having this non-subclass dependecy between two
- classes. But for the moment we have to live with it. This forces us to setup
- this sublocale dependency simultaneously with the lattice operations on finite
- sets, to avoid garbage.
-*}
-
-definition (in semilattice_inf) Inf_fin :: "'a set \<Rightarrow> 'a" ("\<Sqinter>\<^sub>f\<^sub>i\<^sub>n_" [900] 900)
-where
- "Inf_fin = semilattice_set.F inf"
-
-definition (in semilattice_sup) Sup_fin :: "'a set \<Rightarrow> 'a" ("\<Squnion>\<^sub>f\<^sub>i\<^sub>n_" [900] 900)
-where
- "Sup_fin = semilattice_set.F sup"
-
-context linorder
-begin
-
-definition Min :: "'a set \<Rightarrow> 'a"
-where
- "Min = semilattice_set.F min"
-
-definition Max :: "'a set \<Rightarrow> 'a"
-where
- "Max = semilattice_set.F max"
-
-sublocale Min!: semilattice_order_set min less_eq less
- + Max!: semilattice_order_set max greater_eq greater
-where
- "semilattice_set.F min = Min"
- and "semilattice_set.F max = Max"
-proof -
- show "semilattice_order_set min less_eq less" by default (auto simp add: min_def)
- then interpret Min!: semilattice_order_set min less_eq less .
- show "semilattice_order_set max greater_eq greater" by default (auto simp add: max_def)
- then interpret Max!: semilattice_order_set max greater_eq greater .
- from Min_def show "semilattice_set.F min = Min" by rule
- from Max_def show "semilattice_set.F max = Max" by rule
-qed
-
-
-text {* An aside: @{const min}/@{const max} on linear orders as special case of @{const inf}/@{const sup} *}
-
-sublocale min_max!: distrib_lattice min less_eq less max
-where
- "semilattice_inf.Inf_fin min = Min"
- and "semilattice_sup.Sup_fin max = Max"
-proof -
- show "class.distrib_lattice min less_eq less max"
- proof
- fix x y z
- show "max x (min y z) = min (max x y) (max x z)"
- by (auto simp add: min_def max_def)
- qed (auto simp add: min_def max_def not_le less_imp_le)
- then interpret min_max!: distrib_lattice min less_eq less max .
- show "semilattice_inf.Inf_fin min = Min"
- by (simp only: min_max.Inf_fin_def Min_def)
- show "semilattice_sup.Sup_fin max = Max"
- by (simp only: min_max.Sup_fin_def Max_def)
-qed
-
-lemmas le_maxI1 = min_max.sup_ge1
-lemmas le_maxI2 = min_max.sup_ge2
-
-lemmas min_ac = min_max.inf_assoc min_max.inf_commute
- min.left_commute
-
-lemmas max_ac = min_max.sup_assoc min_max.sup_commute
- max.left_commute
-
-end
-
-
-text {* Lattice operations proper *}
-
-sublocale semilattice_inf < Inf_fin!: semilattice_order_set inf less_eq less
-where
- "semilattice_set.F inf = Inf_fin"
-proof -
- show "semilattice_order_set inf less_eq less" ..
- then interpret Inf_fin!: semilattice_order_set inf less_eq less .
- from Inf_fin_def show "semilattice_set.F inf = Inf_fin" by rule
-qed
-
-sublocale semilattice_sup < Sup_fin!: semilattice_order_set sup greater_eq greater
-where
- "semilattice_set.F sup = Sup_fin"
-proof -
- show "semilattice_order_set sup greater_eq greater" ..
- then interpret Sup_fin!: semilattice_order_set sup greater_eq greater .
- from Sup_fin_def show "semilattice_set.F sup = Sup_fin" by rule
-qed
-
-
-text {* An aside again: @{const Min}/@{const Max} on linear orders as special case of @{const Inf_fin}/@{const Sup_fin} *}
-
-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)
-
-
-
-subsection {* Infimum and Supremum over non-empty sets *}
-
-text {*
- After this non-regular bootstrap, things continue canonically.
-*}
-
-context lattice
-begin
-
-lemma Inf_le_Sup [simp]: "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> \<Sqinter>\<^sub>f\<^sub>i\<^sub>nA \<le> \<Squnion>\<^sub>f\<^sub>i\<^sub>nA"
-apply(subgoal_tac "EX a. a:A")
-prefer 2 apply blast
-apply(erule exE)
-apply(rule order_trans)
-apply(erule (1) Inf_fin.coboundedI)
-apply(erule (1) Sup_fin.coboundedI)
-done
-
-lemma sup_Inf_absorb [simp]:
- "finite A \<Longrightarrow> a \<in> A \<Longrightarrow> sup a (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA) = a"
-apply(subst sup_commute)
-apply(simp add: sup_absorb2 Inf_fin.coboundedI)
-done
-
-lemma inf_Sup_absorb [simp]:
- "finite A \<Longrightarrow> a \<in> A \<Longrightarrow> inf a (\<Squnion>\<^sub>f\<^sub>i\<^sub>nA) = a"
-by (simp add: inf_absorb1 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} = (UN a:A. UN b: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} = (UN a:A. UN b: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 = Inf 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 = Sup 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 {* Minimum and Maximum over non-empty sets *}
-
-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_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 `x \<in> A` 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 `x \<in> A` 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
-
-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 Min_antimono:
- assumes "M \<subseteq> N" and "M \<noteq> {}" and "finite N"
- shows "Min N \<le> Min M"
- using assms by (fact Min.antimono)
-
-lemma Max_mono:
- assumes "M \<subseteq> N" and "M \<noteq> {}" and "finite N"
- shows "Max M \<le> Max N"
- using assms by (fact Max.antimono)
-
-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 `finite A` 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 `mono f` have "f (Min A) \<le> f y" by (rule monoE)
- with `x = f y` 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 `finite A` 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 `mono f` have "f y \<le> f (Max A)" by (rule monoE)
- with `x = f y` 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 `P {}` by simp
- next
- let ?B = "A - {Max A}"
- let ?A = "insert (Max A) ?B"
- have "finite ?B" using `finite A` by simp
- assume "A \<noteq> {}"
- with `finite A` have "Max A : A" by auto
- then have A: "?A = A" using insert_Diff_single insert_absorb by auto
- then have "P ?B" using `P {}` step IH [of ?B] by blast
- moreover
- have "\<forall>a\<in>?B. a < Max A" using Max_ge [OF `finite A`] by fastforce
- ultimately show "P A" using A insert_Diff_single step [OF `finite ?B`] 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 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
-
-end
-
-context linordered_ab_semigroup_add
-begin
-
-lemma add_Min_commute:
- fixes k
- assumes "finite N" and "N \<noteq> {}"
- shows "k + Min N = Min {k + m | m. m \<in> N}"
-proof -
- have "\<And>x y. k + min x y = min (k + x) (k + y)"
- by (simp add: min_def not_le)
- (blast intro: antisym less_imp_le add_left_mono)
- with assms show ?thesis
- using hom_Min_commute [of "plus k" N]
- by simp (blast intro: arg_cong [where f = Min])
-qed
-
-lemma add_Max_commute:
- fixes k
- assumes "finite N" and "N \<noteq> {}"
- shows "k + Max N = Max {k + m | m. m \<in> N}"
-proof -
- have "\<And>x y. k + max x y = max (k + x) (k + y)"
- by (simp add: max_def not_le)
- (blast intro: antisym less_imp_le add_left_mono)
- with assms show ?thesis
- using hom_Max_commute [of "plus k" N]
- by simp (blast intro: arg_cong [where f = Max])
-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
-
-end
--- a/src/HOL/Equiv_Relations.thy Sat Dec 14 20:46:36 2013 +0100
+++ b/src/HOL/Equiv_Relations.thy Sun Dec 15 15:10:14 2013 +0100
@@ -5,7 +5,7 @@
header {* Equivalence Relations in Higher-Order Set Theory *}
theory Equiv_Relations
-imports Big_Operators Relation
+imports Groups_Big Relation
begin
subsection {* Equivalence relations -- set version *}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Groups_Big.thy Sun Dec 15 15:10:14 2013 +0100
@@ -0,0 +1,1379 @@
+(* Title: HOL/Groups_Big.thy
+ Author: Tobias Nipkow, Lawrence C Paulson and Markus Wenzel
+ with contributions by Jeremy Avigad
+*)
+
+header {* Big sum and product over finite (non-empty) sets *}
+
+theory Groups_Big
+imports Finite_Set
+begin
+
+subsection {* Generic monoid operation over a set *}
+
+no_notation times (infixl "*" 70)
+no_notation Groups.one ("1")
+
+locale comm_monoid_set = comm_monoid
+begin
+
+interpretation comp_fun_commute f
+ by default (simp add: fun_eq_iff left_commute)
+
+interpretation comp_fun_commute "f \<circ> g"
+ by (rule comp_comp_fun_commute)
+
+definition F :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'a"
+where
+ eq_fold: "F g A = Finite_Set.fold (f \<circ> g) 1 A"
+
+lemma infinite [simp]:
+ "\<not> finite A \<Longrightarrow> F g A = 1"
+ by (simp add: eq_fold)
+
+lemma empty [simp]:
+ "F g {} = 1"
+ by (simp add: eq_fold)
+
+lemma insert [simp]:
+ assumes "finite A" and "x \<notin> A"
+ shows "F g (insert x A) = g x * F g A"
+ using assms by (simp add: eq_fold)
+
+lemma remove:
+ assumes "finite A" and "x \<in> A"
+ shows "F g A = g x * F g (A - {x})"
+proof -
+ from `x \<in> A` obtain B where A: "A = insert x B" and "x \<notin> B"
+ by (auto dest: mk_disjoint_insert)
+ moreover from `finite A` A have "finite B" by simp
+ ultimately show ?thesis by simp
+qed
+
+lemma insert_remove:
+ assumes "finite A"
+ shows "F g (insert x A) = g x * F g (A - {x})"
+ using assms by (cases "x \<in> A") (simp_all add: remove insert_absorb)
+
+lemma neutral:
+ assumes "\<forall>x\<in>A. g x = 1"
+ shows "F g A = 1"
+ using assms by (induct A rule: infinite_finite_induct) simp_all
+
+lemma neutral_const [simp]:
+ "F (\<lambda>_. 1) A = 1"
+ by (simp add: neutral)
+
+lemma union_inter:
+ assumes "finite A" and "finite B"
+ shows "F g (A \<union> B) * F g (A \<inter> B) = F g A * F g B"
+ -- {* The reversed orientation looks more natural, but LOOPS as a simprule! *}
+using assms proof (induct A)
+ case empty then show ?case by simp
+next
+ case (insert x A) then show ?case
+ by (auto simp add: insert_absorb Int_insert_left commute [of _ "g x"] assoc left_commute)
+qed
+
+corollary union_inter_neutral:
+ assumes "finite A" and "finite B"
+ and I0: "\<forall>x \<in> A \<inter> B. g x = 1"
+ shows "F g (A \<union> B) = F g A * F g B"
+ using assms by (simp add: union_inter [symmetric] neutral)
+
+corollary union_disjoint:
+ assumes "finite A" and "finite B"
+ assumes "A \<inter> B = {}"
+ shows "F g (A \<union> B) = F g A * F g B"
+ using assms by (simp add: union_inter_neutral)
+
+lemma subset_diff:
+ assumes "B \<subseteq> A" and "finite A"
+ shows "F g A = F g (A - B) * F g B"
+proof -
+ from assms have "finite (A - B)" by auto
+ moreover from assms have "finite B" by (rule finite_subset)
+ moreover from assms have "(A - B) \<inter> B = {}" by auto
+ ultimately have "F g (A - B \<union> B) = F g (A - B) * F g B" by (rule union_disjoint)
+ moreover from assms have "A \<union> B = A" by auto
+ ultimately show ?thesis by simp
+qed
+
+lemma reindex:
+ assumes "inj_on h A"
+ shows "F g (h ` A) = F (g \<circ> h) A"
+proof (cases "finite A")
+ case True
+ with assms show ?thesis by (simp add: eq_fold fold_image comp_assoc)
+next
+ case False with assms have "\<not> finite (h ` A)" by (blast dest: finite_imageD)
+ with False show ?thesis by simp
+qed
+
+lemma cong:
+ assumes "A = B"
+ assumes g_h: "\<And>x. x \<in> B \<Longrightarrow> g x = h x"
+ shows "F g A = F h B"
+proof (cases "finite A")
+ case True
+ then have "\<And>C. C \<subseteq> A \<longrightarrow> (\<forall>x\<in>C. g x = h x) \<longrightarrow> F g C = F h C"
+ proof induct
+ case empty then show ?case by simp
+ next
+ case (insert x F) then show ?case apply -
+ apply (simp add: subset_insert_iff, clarify)
+ apply (subgoal_tac "finite C")
+ prefer 2 apply (blast dest: finite_subset [rotated])
+ apply (subgoal_tac "C = insert x (C - {x})")
+ prefer 2 apply blast
+ apply (erule ssubst)
+ apply (simp add: Ball_def del: insert_Diff_single)
+ done
+ qed
+ with `A = B` g_h show ?thesis by simp
+next
+ case False
+ with `A = B` show ?thesis by simp
+qed
+
+lemma strong_cong [cong]:
+ assumes "A = B" "\<And>x. x \<in> B =simp=> g x = h x"
+ shows "F (\<lambda>x. g x) A = F (\<lambda>x. h x) B"
+ by (rule cong) (insert assms, simp_all add: simp_implies_def)
+
+lemma UNION_disjoint:
+ assumes "finite I" and "\<forall>i\<in>I. finite (A i)"
+ and "\<forall>i\<in>I. \<forall>j\<in>I. i \<noteq> j \<longrightarrow> A i \<inter> A j = {}"
+ shows "F g (UNION I A) = F (\<lambda>x. F g (A x)) I"
+apply (insert assms)
+apply (induct rule: finite_induct)
+apply simp
+apply atomize
+apply (subgoal_tac "\<forall>i\<in>Fa. x \<noteq> i")
+ prefer 2 apply blast
+apply (subgoal_tac "A x Int UNION Fa A = {}")
+ prefer 2 apply blast
+apply (simp add: union_disjoint)
+done
+
+lemma Union_disjoint:
+ assumes "\<forall>A\<in>C. finite A" "\<forall>A\<in>C. \<forall>B\<in>C. A \<noteq> B \<longrightarrow> A \<inter> B = {}"
+ shows "F g (Union C) = F (F g) C"
+proof cases
+ assume "finite C"
+ from UNION_disjoint [OF this assms]
+ show ?thesis
+ by (simp add: SUP_def)
+qed (auto dest: finite_UnionD intro: infinite)
+
+lemma distrib:
+ "F (\<lambda>x. g x * h x) A = F g A * F h A"
+ using assms by (induct A rule: infinite_finite_induct) (simp_all add: assoc commute left_commute)
+
+lemma Sigma:
+ "finite A \<Longrightarrow> \<forall>x\<in>A. finite (B x) \<Longrightarrow> F (\<lambda>x. F (g x) (B x)) A = F (split g) (SIGMA x:A. B x)"
+apply (subst Sigma_def)
+apply (subst UNION_disjoint, assumption, simp)
+ apply blast
+apply (rule cong)
+apply rule
+apply (simp add: fun_eq_iff)
+apply (subst UNION_disjoint, simp, simp)
+ apply blast
+apply (simp add: comp_def)
+done
+
+lemma related:
+ assumes Re: "R 1 1"
+ and Rop: "\<forall>x1 y1 x2 y2. R x1 x2 \<and> R y1 y2 \<longrightarrow> R (x1 * y1) (x2 * y2)"
+ and fS: "finite S" and Rfg: "\<forall>x\<in>S. R (h x) (g x)"
+ shows "R (F h S) (F g S)"
+ using fS by (rule finite_subset_induct) (insert assms, auto)
+
+lemma eq_general:
+ assumes h: "\<forall>y\<in>S'. \<exists>!x. x \<in> S \<and> h x = y"
+ and f12: "\<forall>x\<in>S. h x \<in> S' \<and> f2 (h x) = f1 x"
+ shows "F f1 S = F f2 S'"
+proof-
+ from h f12 have hS: "h ` S = S'" by blast
+ {fix x y assume H: "x \<in> S" "y \<in> S" "h x = h y"
+ from f12 h H have "x = y" by auto }
+ hence hinj: "inj_on h S" unfolding inj_on_def Ex1_def by blast
+ from f12 have th: "\<And>x. x \<in> S \<Longrightarrow> (f2 \<circ> h) x = f1 x" by auto
+ from hS have "F f2 S' = F f2 (h ` S)" by simp
+ also have "\<dots> = F (f2 o h) S" using reindex [OF hinj, of f2] .
+ also have "\<dots> = F f1 S " using th cong [of _ _ "f2 o h" f1]
+ by blast
+ finally show ?thesis ..
+qed
+
+lemma eq_general_reverses:
+ assumes kh: "\<And>y. y \<in> T \<Longrightarrow> k y \<in> S \<and> h (k y) = y"
+ and hk: "\<And>x. x \<in> S \<Longrightarrow> h x \<in> T \<and> k (h x) = x \<and> g (h x) = j x"
+ shows "F j S = F g T"
+ (* metis solves it, but not yet available here *)
+ apply (rule eq_general [of T S h g j])
+ apply (rule ballI)
+ apply (frule kh)
+ apply (rule ex1I[])
+ apply blast
+ apply clarsimp
+ apply (drule hk) apply simp
+ apply (rule sym)
+ apply (erule conjunct1[OF conjunct2[OF hk]])
+ apply (rule ballI)
+ apply (drule hk)
+ apply blast
+ done
+
+lemma mono_neutral_cong_left:
+ assumes "finite T" and "S \<subseteq> T" and "\<forall>i \<in> T - S. h i = 1"
+ and "\<And>x. x \<in> S \<Longrightarrow> g x = h x" shows "F g S = F h T"
+proof-
+ have eq: "T = S \<union> (T - S)" using `S \<subseteq> T` by blast
+ have d: "S \<inter> (T - S) = {}" using `S \<subseteq> T` by blast
+ from `finite T` `S \<subseteq> T` have f: "finite S" "finite (T - S)"
+ by (auto intro: finite_subset)
+ show ?thesis using assms(4)
+ by (simp add: union_disjoint [OF f d, unfolded eq [symmetric]] neutral [OF assms(3)])
+qed
+
+lemma mono_neutral_cong_right:
+ "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1; \<And>x. x \<in> S \<Longrightarrow> g x = h x \<rbrakk>
+ \<Longrightarrow> F g T = F h S"
+ by (auto intro!: mono_neutral_cong_left [symmetric])
+
+lemma mono_neutral_left:
+ "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1 \<rbrakk> \<Longrightarrow> F g S = F g T"
+ by (blast intro: mono_neutral_cong_left)
+
+lemma mono_neutral_right:
+ "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1 \<rbrakk> \<Longrightarrow> F g T = F g S"
+ by (blast intro!: mono_neutral_left [symmetric])
+
+lemma delta:
+ assumes fS: "finite S"
+ shows "F (\<lambda>k. if k = a then b k else 1) S = (if a \<in> S then b a else 1)"
+proof-
+ let ?f = "(\<lambda>k. if k=a then b k else 1)"
+ { assume a: "a \<notin> S"
+ hence "\<forall>k\<in>S. ?f k = 1" by simp
+ hence ?thesis using a by simp }
+ moreover
+ { assume a: "a \<in> S"
+ let ?A = "S - {a}"
+ let ?B = "{a}"
+ have eq: "S = ?A \<union> ?B" using a by blast
+ have dj: "?A \<inter> ?B = {}" by simp
+ from fS have fAB: "finite ?A" "finite ?B" by auto
+ have "F ?f S = F ?f ?A * F ?f ?B"
+ using union_disjoint [OF fAB dj, of ?f, unfolded eq [symmetric]]
+ by simp
+ then have ?thesis using a by simp }
+ ultimately show ?thesis by blast
+qed
+
+lemma delta':
+ assumes fS: "finite S"
+ shows "F (\<lambda>k. if a = k then b k else 1) S = (if a \<in> S then b a else 1)"
+ using delta [OF fS, of a b, symmetric] by (auto intro: cong)
+
+lemma If_cases:
+ fixes P :: "'b \<Rightarrow> bool" and g h :: "'b \<Rightarrow> 'a"
+ assumes fA: "finite A"
+ shows "F (\<lambda>x. if P x then h x else g x) A =
+ F h (A \<inter> {x. P x}) * F g (A \<inter> - {x. P x})"
+proof -
+ have a: "A = A \<inter> {x. P x} \<union> A \<inter> -{x. P x}"
+ "(A \<inter> {x. P x}) \<inter> (A \<inter> -{x. P x}) = {}"
+ by blast+
+ from fA
+ have f: "finite (A \<inter> {x. P x})" "finite (A \<inter> -{x. P x})" by auto
+ let ?g = "\<lambda>x. if P x then h x else g x"
+ from union_disjoint [OF f a(2), of ?g] a(1)
+ show ?thesis
+ by (subst (1 2) cong) simp_all
+qed
+
+lemma cartesian_product:
+ "F (\<lambda>x. F (g x) B) A = F (split g) (A <*> B)"
+apply (rule sym)
+apply (cases "finite A")
+ apply (cases "finite B")
+ apply (simp add: Sigma)
+ apply (cases "A={}", simp)
+ apply simp
+apply (auto intro: infinite dest: finite_cartesian_productD2)
+apply (cases "B = {}") apply (auto intro: infinite dest: finite_cartesian_productD1)
+done
+
+end
+
+notation times (infixl "*" 70)
+notation Groups.one ("1")
+
+
+subsection {* Generalized summation over a set *}
+
+context comm_monoid_add
+begin
+
+definition setsum :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'a"
+where
+ "setsum = comm_monoid_set.F plus 0"
+
+sublocale setsum!: comm_monoid_set plus 0
+where
+ "comm_monoid_set.F plus 0 = setsum"
+proof -
+ show "comm_monoid_set plus 0" ..
+ then interpret setsum!: comm_monoid_set plus 0 .
+ from setsum_def show "comm_monoid_set.F plus 0 = setsum" by rule
+qed
+
+abbreviation
+ Setsum ("\<Sum>_" [1000] 999) where
+ "\<Sum>A \<equiv> setsum (%x. x) A"
+
+end
+
+text{* Now: lot's of fancy syntax. First, @{term "setsum (%x. e) A"} is
+written @{text"\<Sum>x\<in>A. e"}. *}
+
+syntax
+ "_setsum" :: "pttrn => 'a set => 'b => 'b::comm_monoid_add" ("(3SUM _:_. _)" [0, 51, 10] 10)
+syntax (xsymbols)
+ "_setsum" :: "pttrn => 'a set => 'b => 'b::comm_monoid_add" ("(3\<Sum>_\<in>_. _)" [0, 51, 10] 10)
+syntax (HTML output)
+ "_setsum" :: "pttrn => 'a set => 'b => 'b::comm_monoid_add" ("(3\<Sum>_\<in>_. _)" [0, 51, 10] 10)
+
+translations -- {* Beware of argument permutation! *}
+ "SUM i:A. b" == "CONST setsum (%i. b) A"
+ "\<Sum>i\<in>A. b" == "CONST setsum (%i. b) A"
+
+text{* Instead of @{term"\<Sum>x\<in>{x. P}. e"} we introduce the shorter
+ @{text"\<Sum>x|P. e"}. *}
+
+syntax
+ "_qsetsum" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3SUM _ |/ _./ _)" [0,0,10] 10)
+syntax (xsymbols)
+ "_qsetsum" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Sum>_ | (_)./ _)" [0,0,10] 10)
+syntax (HTML output)
+ "_qsetsum" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Sum>_ | (_)./ _)" [0,0,10] 10)
+
+translations
+ "SUM x|P. t" => "CONST setsum (%x. t) {x. P}"
+ "\<Sum>x|P. t" => "CONST setsum (%x. t) {x. P}"
+
+print_translation {*
+let
+ fun setsum_tr' [Abs (x, Tx, t), Const (@{const_syntax Collect}, _) $ Abs (y, Ty, P)] =
+ if x <> y then raise Match
+ else
+ let
+ val x' = Syntax_Trans.mark_bound_body (x, Tx);
+ val t' = subst_bound (x', t);
+ val P' = subst_bound (x', P);
+ in
+ Syntax.const @{syntax_const "_qsetsum"} $ Syntax_Trans.mark_bound_abs (x, Tx) $ P' $ t'
+ end
+ | setsum_tr' _ = raise Match;
+in [(@{const_syntax setsum}, K setsum_tr')] end
+*}
+
+text {* TODO These are candidates for generalization *}
+
+context comm_monoid_add
+begin
+
+lemma setsum_reindex_id:
+ "inj_on f B ==> setsum f B = setsum id (f ` B)"
+ by (simp add: setsum.reindex)
+
+lemma setsum_reindex_nonzero:
+ assumes fS: "finite S"
+ and nz: "\<And>x y. x \<in> S \<Longrightarrow> y \<in> S \<Longrightarrow> x \<noteq> y \<Longrightarrow> f x = f y \<Longrightarrow> h (f x) = 0"
+ shows "setsum h (f ` S) = setsum (h \<circ> f) S"
+using nz proof (induct rule: finite_induct [OF fS])
+ case 1 thus ?case by simp
+next
+ case (2 x F)
+ { assume fxF: "f x \<in> f ` F" hence "\<exists>y \<in> F . f y = f x" by auto
+ then obtain y where y: "y \<in> F" "f x = f y" by auto
+ from "2.hyps" y have xy: "x \<noteq> y" by auto
+ from "2.prems" [of x y] "2.hyps" xy y have h0: "h (f x) = 0" by simp
+ have "setsum h (f ` insert x F) = setsum h (f ` F)" using fxF by auto
+ also have "\<dots> = setsum (h o f) (insert x F)"
+ unfolding setsum.insert[OF `finite F` `x\<notin>F`]
+ using h0
+ apply (simp cong del: setsum.strong_cong)
+ apply (rule "2.hyps"(3))
+ apply (rule_tac y="y" in "2.prems")
+ apply simp_all
+ done
+ finally have ?case . }
+ moreover
+ { assume fxF: "f x \<notin> f ` F"
+ have "setsum h (f ` insert x F) = h (f x) + setsum h (f ` F)"
+ using fxF "2.hyps" by simp
+ also have "\<dots> = setsum (h o f) (insert x F)"
+ unfolding setsum.insert[OF `finite F` `x\<notin>F`]
+ apply (simp cong del: setsum.strong_cong)
+ apply (rule cong [OF refl [of "op + (h (f x))"]])
+ apply (rule "2.hyps"(3))
+ apply (rule_tac y="y" in "2.prems")
+ apply simp_all
+ done
+ finally have ?case . }
+ ultimately show ?case by blast
+qed
+
+lemma setsum_cong2:
+ "(\<And>x. x \<in> A \<Longrightarrow> f x = g x) \<Longrightarrow> setsum f A = setsum g A"
+ by (auto intro: setsum.cong)
+
+lemma setsum_reindex_cong:
+ "[|inj_on f A; B = f ` A; !!a. a:A \<Longrightarrow> g a = h (f a)|]
+ ==> setsum h B = setsum g A"
+ by (simp add: setsum.reindex)
+
+lemma setsum_restrict_set:
+ assumes fA: "finite A"
+ shows "setsum f (A \<inter> B) = setsum (\<lambda>x. if x \<in> B then f x else 0) A"
+proof-
+ from fA have fab: "finite (A \<inter> B)" by auto
+ have aba: "A \<inter> B \<subseteq> A" by blast
+ let ?g = "\<lambda>x. if x \<in> A\<inter>B then f x else 0"
+ from setsum.mono_neutral_left [OF fA aba, of ?g]
+ show ?thesis by simp
+qed
+
+lemma setsum_Union_disjoint:
+ assumes "\<forall>A\<in>C. finite A" "\<forall>A\<in>C. \<forall>B\<in>C. A \<noteq> B \<longrightarrow> A Int B = {}"
+ shows "setsum f (Union C) = setsum (setsum f) C"
+ using assms by (fact setsum.Union_disjoint)
+
+lemma setsum_cartesian_product:
+ "(\<Sum>x\<in>A. (\<Sum>y\<in>B. f x y)) = (\<Sum>(x,y) \<in> A <*> B. f x y)"
+ by (fact setsum.cartesian_product)
+
+lemma setsum_UNION_zero:
+ assumes fS: "finite S" and fSS: "\<forall>T \<in> S. finite T"
+ and f0: "\<And>T1 T2 x. T1\<in>S \<Longrightarrow> T2\<in>S \<Longrightarrow> T1 \<noteq> T2 \<Longrightarrow> x \<in> T1 \<Longrightarrow> x \<in> T2 \<Longrightarrow> f x = 0"
+ shows "setsum f (\<Union>S) = setsum (\<lambda>T. setsum f T) S"
+ using fSS f0
+proof(induct rule: finite_induct[OF fS])
+ case 1 thus ?case by simp
+next
+ case (2 T F)
+ then have fTF: "finite T" "\<forall>T\<in>F. finite T" "finite F" and TF: "T \<notin> F"
+ and H: "setsum f (\<Union> F) = setsum (setsum f) F" by auto
+ from fTF have fUF: "finite (\<Union>F)" by auto
+ from "2.prems" TF fTF
+ show ?case
+ by (auto simp add: H [symmetric] intro: setsum.union_inter_neutral [OF fTF(1) fUF, of f])
+qed
+
+text {* Commuting outer and inner summation *}
+
+lemma setsum_commute:
+ "(\<Sum>i\<in>A. \<Sum>j\<in>B. f i j) = (\<Sum>j\<in>B. \<Sum>i\<in>A. f i j)"
+proof (simp add: setsum_cartesian_product)
+ have "(\<Sum>(x,y) \<in> A <*> B. f x y) =
+ (\<Sum>(y,x) \<in> (%(i, j). (j, i)) ` (A \<times> B). f x y)"
+ (is "?s = _")
+ apply (simp add: setsum.reindex [where h = "%(i, j). (j, i)"] swap_inj_on)
+ apply (simp add: split_def)
+ done
+ also have "... = (\<Sum>(y,x)\<in>B \<times> A. f x y)"
+ (is "_ = ?t")
+ apply (simp add: swap_product)
+ done
+ finally show "?s = ?t" .
+qed
+
+lemma setsum_Plus:
+ fixes A :: "'a set" and B :: "'b set"
+ assumes fin: "finite A" "finite B"
+ shows "setsum f (A <+> B) = setsum (f \<circ> Inl) A + setsum (f \<circ> Inr) B"
+proof -
+ have "A <+> B = Inl ` A \<union> Inr ` B" by auto
+ moreover from fin have "finite (Inl ` A :: ('a + 'b) set)" "finite (Inr ` B :: ('a + 'b) set)"
+ by auto
+ moreover have "Inl ` A \<inter> Inr ` B = ({} :: ('a + 'b) set)" by auto
+ moreover have "inj_on (Inl :: 'a \<Rightarrow> 'a + 'b) A" "inj_on (Inr :: 'b \<Rightarrow> 'a + 'b) B" by(auto intro: inj_onI)
+ ultimately show ?thesis using fin by(simp add: setsum.union_disjoint setsum.reindex)
+qed
+
+end
+
+text {* TODO These are legacy *}
+
+lemma setsum_empty:
+ "setsum f {} = 0"
+ by (fact setsum.empty)
+
+lemma setsum_insert:
+ "finite F ==> a \<notin> F ==> setsum f (insert a F) = f a + setsum f F"
+ by (fact setsum.insert)
+
+lemma setsum_infinite:
+ "~ finite A ==> setsum f A = 0"
+ by (fact setsum.infinite)
+
+lemma setsum_reindex:
+ "inj_on f B \<Longrightarrow> setsum h (f ` B) = setsum (h \<circ> f) B"
+ by (fact setsum.reindex)
+
+lemma setsum_cong:
+ "A = B ==> (!!x. x:B ==> f x = g x) ==> setsum f A = setsum g B"
+ by (fact setsum.cong)
+
+lemma strong_setsum_cong:
+ "A = B ==> (!!x. x:B =simp=> f x = g x)
+ ==> setsum (%x. f x) A = setsum (%x. g x) B"
+ by (fact setsum.strong_cong)
+
+lemmas setsum_0 = setsum.neutral_const
+lemmas setsum_0' = setsum.neutral
+
+lemma setsum_Un_Int: "finite A ==> finite B ==>
+ setsum g (A Un B) + setsum g (A Int B) = setsum g A + setsum g B"
+ -- {* The reversed orientation looks more natural, but LOOPS as a simprule! *}
+ by (fact setsum.union_inter)
+
+lemma setsum_Un_disjoint: "finite A ==> finite B
+ ==> A Int B = {} ==> setsum g (A Un B) = setsum g A + setsum g B"
+ by (fact setsum.union_disjoint)
+
+lemma setsum_subset_diff: "\<lbrakk> B \<subseteq> A; finite A \<rbrakk> \<Longrightarrow>
+ setsum f A = setsum f (A - B) + setsum f B"
+ by (fact setsum.subset_diff)
+
+lemma setsum_mono_zero_left:
+ "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. f i = 0 \<rbrakk> \<Longrightarrow> setsum f S = setsum f T"
+ by (fact setsum.mono_neutral_left)
+
+lemmas setsum_mono_zero_right = setsum.mono_neutral_right
+
+lemma setsum_mono_zero_cong_left:
+ "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 0; \<And>x. x \<in> S \<Longrightarrow> f x = g x \<rbrakk>
+ \<Longrightarrow> setsum f S = setsum g T"
+ by (fact setsum.mono_neutral_cong_left)
+
+lemmas setsum_mono_zero_cong_right = setsum.mono_neutral_cong_right
+
+lemma setsum_delta: "finite S \<Longrightarrow>
+ setsum (\<lambda>k. if k=a then b k else 0) S = (if a \<in> S then b a else 0)"
+ by (fact setsum.delta)
+
+lemma setsum_delta': "finite S \<Longrightarrow>
+ setsum (\<lambda>k. if a = k then b k else 0) S = (if a\<in> S then b a else 0)"
+ by (fact setsum.delta')
+
+lemma setsum_cases:
+ assumes "finite A"
+ shows "setsum (\<lambda>x. if P x then f x else g x) A =
+ setsum f (A \<inter> {x. P x}) + setsum g (A \<inter> - {x. P x})"
+ using assms by (fact setsum.If_cases)
+
+(*But we can't get rid of finite I. If infinite, although the rhs is 0,
+ the lhs need not be, since UNION I A could still be finite.*)
+lemma setsum_UN_disjoint:
+ assumes "finite I" and "ALL i:I. finite (A i)"
+ and "ALL i:I. ALL j:I. i \<noteq> j --> A i Int A j = {}"
+ shows "setsum f (UNION I A) = (\<Sum>i\<in>I. setsum f (A i))"
+ using assms by (fact setsum.UNION_disjoint)
+
+(*But we can't get rid of finite A. If infinite, although the lhs is 0,
+ the rhs need not be, since SIGMA A B could still be finite.*)
+lemma setsum_Sigma:
+ assumes "finite A" and "ALL x:A. finite (B x)"
+ shows "(\<Sum>x\<in>A. (\<Sum>y\<in>B x. f x y)) = (\<Sum>(x,y)\<in>(SIGMA x:A. B x). f x y)"
+ using assms by (fact setsum.Sigma)
+
+lemma setsum_addf: "setsum (%x. f x + g x) A = (setsum f A + setsum g A)"
+ by (fact setsum.distrib)
+
+lemma setsum_Un_zero:
+ "\<lbrakk> finite S; finite T; \<forall>x \<in> S\<inter>T. f x = 0 \<rbrakk> \<Longrightarrow>
+ setsum f (S \<union> T) = setsum f S + setsum f T"
+ by (fact setsum.union_inter_neutral)
+
+lemma setsum_eq_general_reverses:
+ assumes fS: "finite S" and fT: "finite T"
+ and kh: "\<And>y. y \<in> T \<Longrightarrow> k y \<in> S \<and> h (k y) = y"
+ and hk: "\<And>x. x \<in> S \<Longrightarrow> h x \<in> T \<and> k (h x) = x \<and> g (h x) = f x"
+ shows "setsum f S = setsum g T"
+ using kh hk by (fact setsum.eq_general_reverses)
+
+
+subsubsection {* Properties in more restricted classes of structures *}
+
+lemma setsum_Un: "finite A ==> finite B ==>
+ (setsum f (A Un B) :: 'a :: ab_group_add) =
+ setsum f A + setsum f B - setsum f (A Int B)"
+by (subst setsum_Un_Int [symmetric], auto simp add: algebra_simps)
+
+lemma setsum_Un2:
+ assumes "finite (A \<union> B)"
+ shows "setsum f (A \<union> B) = setsum f (A - B) + setsum f (B - A) + setsum f (A \<inter> B)"
+proof -
+ have "A \<union> B = A - B \<union> (B - A) \<union> A \<inter> B"
+ by auto
+ with assms show ?thesis by simp (subst setsum_Un_disjoint, auto)+
+qed
+
+lemma setsum_diff1: "finite A \<Longrightarrow>
+ (setsum f (A - {a}) :: ('a::ab_group_add)) =
+ (if a:A then setsum f A - f a else setsum f A)"
+by (erule finite_induct) (auto simp add: insert_Diff_if)
+
+lemma setsum_diff:
+ assumes le: "finite A" "B \<subseteq> A"
+ shows "setsum f (A - B) = setsum f A - ((setsum f B)::('a::ab_group_add))"
+proof -
+ from le have finiteB: "finite B" using finite_subset by auto
+ show ?thesis using finiteB le
+ proof induct
+ case empty
+ thus ?case by auto
+ next
+ case (insert x F)
+ thus ?case using le finiteB
+ by (simp add: Diff_insert[where a=x and B=F] setsum_diff1 insert_absorb)
+ qed
+qed
+
+lemma setsum_mono:
+ assumes le: "\<And>i. i\<in>K \<Longrightarrow> f (i::'a) \<le> ((g i)::('b::{comm_monoid_add, ordered_ab_semigroup_add}))"
+ shows "(\<Sum>i\<in>K. f i) \<le> (\<Sum>i\<in>K. g i)"
+proof (cases "finite K")
+ case True
+ thus ?thesis using le
+ proof induct
+ case empty
+ thus ?case by simp
+ next
+ case insert
+ thus ?case using add_mono by fastforce
+ qed
+next
+ case False then show ?thesis by simp
+qed
+
+lemma setsum_strict_mono:
+ fixes f :: "'a \<Rightarrow> 'b::{ordered_cancel_ab_semigroup_add,comm_monoid_add}"
+ assumes "finite A" "A \<noteq> {}"
+ and "!!x. x:A \<Longrightarrow> f x < g x"
+ shows "setsum f A < setsum g A"
+ using assms
+proof (induct rule: finite_ne_induct)
+ case singleton thus ?case by simp
+next
+ case insert thus ?case by (auto simp: add_strict_mono)
+qed
+
+lemma setsum_strict_mono_ex1:
+fixes f :: "'a \<Rightarrow> 'b::{comm_monoid_add, ordered_cancel_ab_semigroup_add}"
+assumes "finite A" and "ALL x:A. f x \<le> g x" and "EX a:A. f a < g a"
+shows "setsum f A < setsum g A"
+proof-
+ from assms(3) obtain a where a: "a:A" "f a < g a" by blast
+ have "setsum f A = setsum f ((A-{a}) \<union> {a})"
+ by(simp add:insert_absorb[OF `a:A`])
+ also have "\<dots> = setsum f (A-{a}) + setsum f {a}"
+ using `finite A` by(subst setsum_Un_disjoint) auto
+ also have "setsum f (A-{a}) \<le> setsum g (A-{a})"
+ by(rule setsum_mono)(simp add: assms(2))
+ also have "setsum f {a} < setsum g {a}" using a by simp
+ also have "setsum g (A - {a}) + setsum g {a} = setsum g((A-{a}) \<union> {a})"
+ using `finite A` by(subst setsum_Un_disjoint[symmetric]) auto
+ also have "\<dots> = setsum g A" by(simp add:insert_absorb[OF `a:A`])
+ finally show ?thesis by (auto simp add: add_right_mono add_strict_left_mono)
+qed
+
+lemma setsum_negf:
+ "setsum (%x. - (f x)::'a::ab_group_add) A = - setsum f A"
+proof (cases "finite A")
+ case True thus ?thesis by (induct set: finite) auto
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_subtractf:
+ "setsum (%x. ((f x)::'a::ab_group_add) - g x) A =
+ setsum f A - setsum g A"
+ using setsum_addf [of f "- g" A] by (simp add: setsum_negf)
+
+lemma setsum_nonneg:
+ assumes nn: "\<forall>x\<in>A. (0::'a::{ordered_ab_semigroup_add,comm_monoid_add}) \<le> f x"
+ shows "0 \<le> setsum f A"
+proof (cases "finite A")
+ case True thus ?thesis using nn
+ proof induct
+ case empty then show ?case by simp
+ next
+ case (insert x F)
+ then have "0 + 0 \<le> f x + setsum f F" by (blast intro: add_mono)
+ with insert show ?case by simp
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_nonpos:
+ assumes np: "\<forall>x\<in>A. f x \<le> (0::'a::{ordered_ab_semigroup_add,comm_monoid_add})"
+ shows "setsum f A \<le> 0"
+proof (cases "finite A")
+ case True thus ?thesis using np
+ proof induct
+ case empty then show ?case by simp
+ next
+ case (insert x F)
+ then have "f x + setsum f F \<le> 0 + 0" by (blast intro: add_mono)
+ with insert show ?case by simp
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_nonneg_leq_bound:
+ fixes f :: "'a \<Rightarrow> 'b::{ordered_ab_group_add}"
+ assumes "finite s" "\<And>i. i \<in> s \<Longrightarrow> f i \<ge> 0" "(\<Sum>i \<in> s. f i) = B" "i \<in> s"
+ shows "f i \<le> B"
+proof -
+ have "0 \<le> (\<Sum> i \<in> s - {i}. f i)" and "0 \<le> f i"
+ using assms by (auto intro!: setsum_nonneg)
+ moreover
+ have "(\<Sum> i \<in> s - {i}. f i) + f i = B"
+ using assms by (simp add: setsum_diff1)
+ ultimately show ?thesis by auto
+qed
+
+lemma setsum_nonneg_0:
+ fixes f :: "'a \<Rightarrow> 'b::{ordered_ab_group_add}"
+ assumes "finite s" and pos: "\<And> i. i \<in> s \<Longrightarrow> f i \<ge> 0"
+ and "(\<Sum> i \<in> s. f i) = 0" and i: "i \<in> s"
+ shows "f i = 0"
+ using setsum_nonneg_leq_bound[OF assms] pos[OF i] by auto
+
+lemma setsum_mono2:
+fixes f :: "'a \<Rightarrow> 'b :: ordered_comm_monoid_add"
+assumes fin: "finite B" and sub: "A \<subseteq> B" and nn: "\<And>b. b \<in> B-A \<Longrightarrow> 0 \<le> f b"
+shows "setsum f A \<le> setsum f B"
+proof -
+ have "setsum f A \<le> setsum f A + setsum f (B-A)"
+ by(simp add: add_increasing2[OF setsum_nonneg] nn Ball_def)
+ also have "\<dots> = setsum f (A \<union> (B-A))" using fin finite_subset[OF sub fin]
+ by (simp add:setsum_Un_disjoint del:Un_Diff_cancel)
+ also have "A \<union> (B-A) = B" using sub by blast
+ finally show ?thesis .
+qed
+
+lemma setsum_mono3: "finite B ==> A <= B ==>
+ ALL x: B - A.
+ 0 <= ((f x)::'a::{comm_monoid_add,ordered_ab_semigroup_add}) ==>
+ setsum f A <= setsum f B"
+ apply (subgoal_tac "setsum f B = setsum f A + setsum f (B - A)")
+ apply (erule ssubst)
+ apply (subgoal_tac "setsum f A + 0 <= setsum f A + setsum f (B - A)")
+ apply simp
+ apply (rule add_left_mono)
+ apply (erule setsum_nonneg)
+ apply (subst setsum_Un_disjoint [THEN sym])
+ apply (erule finite_subset, assumption)
+ apply (rule finite_subset)
+ prefer 2
+ apply assumption
+ apply (auto simp add: sup_absorb2)
+done
+
+lemma setsum_right_distrib:
+ fixes f :: "'a => ('b::semiring_0)"
+ shows "r * setsum f A = setsum (%n. r * f n) A"
+proof (cases "finite A")
+ case True
+ thus ?thesis
+ proof induct
+ case empty thus ?case by simp
+ next
+ case (insert x A) thus ?case by (simp add: distrib_left)
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_left_distrib:
+ "setsum f A * (r::'a::semiring_0) = (\<Sum>n\<in>A. f n * r)"
+proof (cases "finite A")
+ case True
+ then show ?thesis
+ proof induct
+ case empty thus ?case by simp
+ next
+ case (insert x A) thus ?case by (simp add: distrib_right)
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_divide_distrib:
+ "setsum f A / (r::'a::field) = (\<Sum>n\<in>A. f n / r)"
+proof (cases "finite A")
+ case True
+ then show ?thesis
+ proof induct
+ case empty thus ?case by simp
+ next
+ case (insert x A) thus ?case by (simp add: add_divide_distrib)
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_abs[iff]:
+ fixes f :: "'a => ('b::ordered_ab_group_add_abs)"
+ shows "abs (setsum f A) \<le> setsum (%i. abs(f i)) A"
+proof (cases "finite A")
+ case True
+ thus ?thesis
+ proof induct
+ case empty thus ?case by simp
+ next
+ case (insert x A)
+ thus ?case by (auto intro: abs_triangle_ineq order_trans)
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_abs_ge_zero[iff]:
+ fixes f :: "'a => ('b::ordered_ab_group_add_abs)"
+ shows "0 \<le> setsum (%i. abs(f i)) A"
+proof (cases "finite A")
+ case True
+ thus ?thesis
+ proof induct
+ case empty thus ?case by simp
+ next
+ case (insert x A) thus ?case by auto
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma abs_setsum_abs[simp]:
+ fixes f :: "'a => ('b::ordered_ab_group_add_abs)"
+ shows "abs (\<Sum>a\<in>A. abs(f a)) = (\<Sum>a\<in>A. abs(f a))"
+proof (cases "finite A")
+ case True
+ thus ?thesis
+ proof induct
+ case empty thus ?case by simp
+ next
+ case (insert a A)
+ hence "\<bar>\<Sum>a\<in>insert a A. \<bar>f a\<bar>\<bar> = \<bar>\<bar>f a\<bar> + (\<Sum>a\<in>A. \<bar>f a\<bar>)\<bar>" by simp
+ also have "\<dots> = \<bar>\<bar>f a\<bar> + \<bar>\<Sum>a\<in>A. \<bar>f a\<bar>\<bar>\<bar>" using insert by simp
+ also have "\<dots> = \<bar>f a\<bar> + \<bar>\<Sum>a\<in>A. \<bar>f a\<bar>\<bar>"
+ by (simp del: abs_of_nonneg)
+ also have "\<dots> = (\<Sum>a\<in>insert a A. \<bar>f a\<bar>)" using insert by simp
+ finally show ?case .
+ qed
+next
+ case False thus ?thesis by simp
+qed
+
+lemma setsum_diff1'[rule_format]:
+ "finite A \<Longrightarrow> a \<in> A \<longrightarrow> (\<Sum> x \<in> A. f x) = f a + (\<Sum> x \<in> (A - {a}). f x)"
+apply (erule finite_induct[where F=A and P="% A. (a \<in> A \<longrightarrow> (\<Sum> x \<in> A. f x) = f a + (\<Sum> x \<in> (A - {a}). f x))"])
+apply (auto simp add: insert_Diff_if add_ac)
+done
+
+lemma setsum_diff1_ring: assumes "finite A" "a \<in> A"
+ shows "setsum f (A - {a}) = setsum f A - (f a::'a::ring)"
+unfolding setsum_diff1'[OF assms] by auto
+
+lemma setsum_product:
+ fixes f :: "'a => ('b::semiring_0)"
+ shows "setsum f A * setsum g B = (\<Sum>i\<in>A. \<Sum>j\<in>B. f i * g j)"
+ by (simp add: setsum_right_distrib setsum_left_distrib) (rule setsum_commute)
+
+lemma setsum_mult_setsum_if_inj:
+fixes f :: "'a => ('b::semiring_0)"
+shows "inj_on (%(a,b). f a * g b) (A \<times> B) ==>
+ setsum f A * setsum g B = setsum id {f a * g b|a b. a:A & b:B}"
+by(auto simp: setsum_product setsum_cartesian_product
+ intro!: setsum_reindex_cong[symmetric])
+
+lemma setsum_SucD: "setsum f A = Suc n ==> EX a:A. 0 < f a"
+apply (case_tac "finite A")
+ prefer 2 apply simp
+apply (erule rev_mp)
+apply (erule finite_induct, auto)
+done
+
+lemma setsum_eq_0_iff [simp]:
+ "finite F ==> (setsum f F = 0) = (ALL a:F. f a = (0::nat))"
+ by (induct set: finite) auto
+
+lemma setsum_eq_Suc0_iff: "finite A \<Longrightarrow>
+ setsum f A = Suc 0 \<longleftrightarrow> (EX a:A. f a = Suc 0 & (ALL b:A. a\<noteq>b \<longrightarrow> f b = 0))"
+apply(erule finite_induct)
+apply (auto simp add:add_is_1)
+done
+
+lemmas setsum_eq_1_iff = setsum_eq_Suc0_iff[simplified One_nat_def[symmetric]]
+
+lemma setsum_Un_nat: "finite A ==> finite B ==>
+ (setsum f (A Un B) :: nat) = setsum f A + setsum f B - setsum f (A Int B)"
+ -- {* For the natural numbers, we have subtraction. *}
+by (subst setsum_Un_Int [symmetric], auto simp add: algebra_simps)
+
+lemma setsum_diff1_nat: "(setsum f (A - {a}) :: nat) =
+ (if a:A then setsum f A - f a else setsum f A)"
+apply (case_tac "finite A")
+ prefer 2 apply simp
+apply (erule finite_induct)
+ apply (auto simp add: insert_Diff_if)
+apply (drule_tac a = a in mk_disjoint_insert, auto)
+done
+
+lemma setsum_diff_nat:
+assumes "finite B" and "B \<subseteq> A"
+shows "(setsum f (A - B) :: nat) = (setsum f A) - (setsum f B)"
+using assms
+proof induct
+ show "setsum f (A - {}) = (setsum f A) - (setsum f {})" by simp
+next
+ fix F x assume finF: "finite F" and xnotinF: "x \<notin> F"
+ and xFinA: "insert x F \<subseteq> A"
+ and IH: "F \<subseteq> A \<Longrightarrow> setsum f (A - F) = setsum f A - setsum f F"
+ from xnotinF xFinA have xinAF: "x \<in> (A - F)" by simp
+ from xinAF have A: "setsum f ((A - F) - {x}) = setsum f (A - F) - f x"
+ by (simp add: setsum_diff1_nat)
+ from xFinA have "F \<subseteq> A" by simp
+ with IH have "setsum f (A - F) = setsum f A - setsum f F" by simp
+ with A have B: "setsum f ((A - F) - {x}) = setsum f A - setsum f F - f x"
+ by simp
+ from xnotinF have "A - insert x F = (A - F) - {x}" by auto
+ with B have C: "setsum f (A - insert x F) = setsum f A - setsum f F - f x"
+ by simp
+ from finF xnotinF have "setsum f (insert x F) = setsum f F + f x" by simp
+ with C have "setsum f (A - insert x F) = setsum f A - setsum f (insert x F)"
+ by simp
+ thus "setsum f (A - insert x F) = setsum f A - setsum f (insert x F)" by simp
+qed
+
+lemma setsum_comp_morphism:
+ assumes "h 0 = 0" and "\<And>x y. h (x + y) = h x + h y"
+ shows "setsum (h \<circ> g) A = h (setsum g A)"
+proof (cases "finite A")
+ case False then show ?thesis by (simp add: assms)
+next
+ case True then show ?thesis by (induct A) (simp_all add: assms)
+qed
+
+
+subsubsection {* Cardinality as special case of @{const setsum} *}
+
+lemma card_eq_setsum:
+ "card A = setsum (\<lambda>x. 1) A"
+proof -
+ have "plus \<circ> (\<lambda>_. Suc 0) = (\<lambda>_. Suc)"
+ by (simp add: fun_eq_iff)
+ then have "Finite_Set.fold (plus \<circ> (\<lambda>_. Suc 0)) = Finite_Set.fold (\<lambda>_. Suc)"
+ by (rule arg_cong)
+ then have "Finite_Set.fold (plus \<circ> (\<lambda>_. Suc 0)) 0 A = Finite_Set.fold (\<lambda>_. Suc) 0 A"
+ by (blast intro: fun_cong)
+ then show ?thesis by (simp add: card.eq_fold setsum.eq_fold)
+qed
+
+lemma setsum_constant [simp]:
+ "(\<Sum>x \<in> A. y) = of_nat (card A) * y"
+apply (cases "finite A")
+apply (erule finite_induct)
+apply (auto simp add: algebra_simps)
+done
+
+lemma setsum_bounded:
+ assumes le: "\<And>i. i\<in>A \<Longrightarrow> f i \<le> (K::'a::{semiring_1, ordered_ab_semigroup_add})"
+ shows "setsum f A \<le> of_nat (card A) * K"
+proof (cases "finite A")
+ case True
+ thus ?thesis using le setsum_mono[where K=A and g = "%x. K"] by simp
+next
+ case False thus ?thesis by simp
+qed
+
+lemma card_UN_disjoint:
+ assumes "finite I" and "\<forall>i\<in>I. finite (A i)"
+ and "\<forall>i\<in>I. \<forall>j\<in>I. i \<noteq> j \<longrightarrow> A i \<inter> A j = {}"
+ shows "card (UNION I A) = (\<Sum>i\<in>I. card(A i))"
+proof -
+ have "(\<Sum>i\<in>I. card (A i)) = (\<Sum>i\<in>I. \<Sum>x\<in>A i. 1)" by simp
+ with assms show ?thesis by (simp add: card_eq_setsum setsum_UN_disjoint del: setsum_constant)
+qed
+
+lemma card_Union_disjoint:
+ "finite C ==> (ALL A:C. finite A) ==>
+ (ALL A:C. ALL B:C. A \<noteq> B --> A Int B = {})
+ ==> card (Union C) = setsum card C"
+apply (frule card_UN_disjoint [of C id])
+apply (simp_all add: SUP_def id_def)
+done
+
+
+subsubsection {* Cardinality of products *}
+
+lemma card_SigmaI [simp]:
+ "\<lbrakk> finite A; ALL a:A. finite (B a) \<rbrakk>
+ \<Longrightarrow> card (SIGMA x: A. B x) = (\<Sum>a\<in>A. card (B a))"
+by(simp add: card_eq_setsum setsum_Sigma del:setsum_constant)
+
+(*
+lemma SigmaI_insert: "y \<notin> A ==>
+ (SIGMA x:(insert y A). B x) = (({y} <*> (B y)) \<union> (SIGMA x: A. B x))"
+ by auto
+*)
+
+lemma card_cartesian_product: "card (A <*> B) = card(A) * card(B)"
+ by (cases "finite A \<and> finite B")
+ (auto simp add: card_eq_0_iff dest: finite_cartesian_productD1 finite_cartesian_productD2)
+
+lemma card_cartesian_product_singleton: "card({x} <*> A) = card(A)"
+by (simp add: card_cartesian_product)
+
+
+subsection {* Generalized product over a set *}
+
+context comm_monoid_mult
+begin
+
+definition setprod :: "('b \<Rightarrow> 'a) \<Rightarrow> 'b set \<Rightarrow> 'a"
+where
+ "setprod = comm_monoid_set.F times 1"
+
+sublocale setprod!: comm_monoid_set times 1
+where
+ "comm_monoid_set.F times 1 = setprod"
+proof -
+ show "comm_monoid_set times 1" ..
+ then interpret setprod!: comm_monoid_set times 1 .
+ from setprod_def show "comm_monoid_set.F times 1 = setprod" by rule
+qed
+
+abbreviation
+ Setprod ("\<Prod>_" [1000] 999) where
+ "\<Prod>A \<equiv> setprod (\<lambda>x. x) A"
+
+end
+
+syntax
+ "_setprod" :: "pttrn => 'a set => 'b => 'b::comm_monoid_mult" ("(3PROD _:_. _)" [0, 51, 10] 10)
+syntax (xsymbols)
+ "_setprod" :: "pttrn => 'a set => 'b => 'b::comm_monoid_mult" ("(3\<Prod>_\<in>_. _)" [0, 51, 10] 10)
+syntax (HTML output)
+ "_setprod" :: "pttrn => 'a set => 'b => 'b::comm_monoid_mult" ("(3\<Prod>_\<in>_. _)" [0, 51, 10] 10)
+
+translations -- {* Beware of argument permutation! *}
+ "PROD i:A. b" == "CONST setprod (%i. b) A"
+ "\<Prod>i\<in>A. b" == "CONST setprod (%i. b) A"
+
+text{* Instead of @{term"\<Prod>x\<in>{x. P}. e"} we introduce the shorter
+ @{text"\<Prod>x|P. e"}. *}
+
+syntax
+ "_qsetprod" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3PROD _ |/ _./ _)" [0,0,10] 10)
+syntax (xsymbols)
+ "_qsetprod" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Prod>_ | (_)./ _)" [0,0,10] 10)
+syntax (HTML output)
+ "_qsetprod" :: "pttrn \<Rightarrow> bool \<Rightarrow> 'a \<Rightarrow> 'a" ("(3\<Prod>_ | (_)./ _)" [0,0,10] 10)
+
+translations
+ "PROD x|P. t" => "CONST setprod (%x. t) {x. P}"
+ "\<Prod>x|P. t" => "CONST setprod (%x. t) {x. P}"
+
+text {* TODO These are candidates for generalization *}
+
+context comm_monoid_mult
+begin
+
+lemma setprod_reindex_id:
+ "inj_on f B ==> setprod f B = setprod id (f ` B)"
+ by (auto simp add: setprod.reindex)
+
+lemma setprod_reindex_cong:
+ "inj_on f A ==> B = f ` A ==> g = h \<circ> f ==> setprod h B = setprod g A"
+ by (frule setprod.reindex, simp)
+
+lemma strong_setprod_reindex_cong:
+ assumes i: "inj_on f A"
+ and B: "B = f ` A" and eq: "\<And>x. x \<in> A \<Longrightarrow> g x = (h \<circ> f) x"
+ shows "setprod h B = setprod g A"
+proof-
+ have "setprod h B = setprod (h o f) A"
+ by (simp add: B setprod.reindex [OF i, of h])
+ then show ?thesis apply simp
+ apply (rule setprod.cong)
+ apply simp
+ by (simp add: eq)
+qed
+
+lemma setprod_Union_disjoint:
+ assumes "\<forall>A\<in>C. finite A" "\<forall>A\<in>C. \<forall>B\<in>C. A \<noteq> B \<longrightarrow> A Int B = {}"
+ shows "setprod f (Union C) = setprod (setprod f) C"
+ using assms by (fact setprod.Union_disjoint)
+
+text{*Here we can eliminate the finiteness assumptions, by cases.*}
+lemma setprod_cartesian_product:
+ "(\<Prod>x\<in>A. (\<Prod>y\<in> B. f x y)) = (\<Prod>(x,y)\<in>(A <*> B). f x y)"
+ by (fact setprod.cartesian_product)
+
+lemma setprod_Un2:
+ assumes "finite (A \<union> B)"
+ shows "setprod f (A \<union> B) = setprod f (A - B) * setprod f (B - A) * setprod f (A \<inter> B)"
+proof -
+ have "A \<union> B = A - B \<union> (B - A) \<union> A \<inter> B"
+ by auto
+ with assms show ?thesis by simp (subst setprod.union_disjoint, auto)+
+qed
+
+end
+
+text {* TODO These are legacy *}
+
+lemma setprod_empty: "setprod f {} = 1"
+ by (fact setprod.empty)
+
+lemma setprod_insert: "[| finite A; a \<notin> A |] ==>
+ setprod f (insert a A) = f a * setprod f A"
+ by (fact setprod.insert)
+
+lemma setprod_infinite: "~ finite A ==> setprod f A = 1"
+ by (fact setprod.infinite)
+
+lemma setprod_reindex:
+ "inj_on f B ==> setprod h (f ` B) = setprod (h \<circ> f) B"
+ by (fact setprod.reindex)
+
+lemma setprod_cong:
+ "A = B ==> (!!x. x:B ==> f x = g x) ==> setprod f A = setprod g B"
+ by (fact setprod.cong)
+
+lemma strong_setprod_cong:
+ "A = B ==> (!!x. x:B =simp=> f x = g x) ==> setprod f A = setprod g B"
+ by (fact setprod.strong_cong)
+
+lemma setprod_Un_one:
+ "\<lbrakk> finite S; finite T; \<forall>x \<in> S\<inter>T. f x = 1 \<rbrakk>
+ \<Longrightarrow> setprod f (S \<union> T) = setprod f S * setprod f T"
+ by (fact setprod.union_inter_neutral)
+
+lemmas setprod_1 = setprod.neutral_const
+lemmas setprod_1' = setprod.neutral
+
+lemma setprod_Un_Int: "finite A ==> finite B
+ ==> setprod g (A Un B) * setprod g (A Int B) = setprod g A * setprod g B"
+ by (fact setprod.union_inter)
+
+lemma setprod_Un_disjoint: "finite A ==> finite B
+ ==> A Int B = {} ==> setprod g (A Un B) = setprod g A * setprod g B"
+ by (fact setprod.union_disjoint)
+
+lemma setprod_subset_diff: "\<lbrakk> B \<subseteq> A; finite A \<rbrakk> \<Longrightarrow>
+ setprod f A = setprod f (A - B) * setprod f B"
+ by (fact setprod.subset_diff)
+
+lemma setprod_mono_one_left:
+ "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. f i = 1 \<rbrakk> \<Longrightarrow> setprod f S = setprod f T"
+ by (fact setprod.mono_neutral_left)
+
+lemmas setprod_mono_one_right = setprod.mono_neutral_right
+
+lemma setprod_mono_one_cong_left:
+ "\<lbrakk> finite T; S \<subseteq> T; \<forall>i \<in> T - S. g i = 1; \<And>x. x \<in> S \<Longrightarrow> f x = g x \<rbrakk>
+ \<Longrightarrow> setprod f S = setprod g T"
+ by (fact setprod.mono_neutral_cong_left)
+
+lemmas setprod_mono_one_cong_right = setprod.mono_neutral_cong_right
+
+lemma setprod_delta: "finite S \<Longrightarrow>
+ setprod (\<lambda>k. if k=a then b k else 1) S = (if a \<in> S then b a else 1)"
+ by (fact setprod.delta)
+
+lemma setprod_delta': "finite S \<Longrightarrow>
+ setprod (\<lambda>k. if a = k then b k else 1) S = (if a\<in> S then b a else 1)"
+ by (fact setprod.delta')
+
+lemma setprod_UN_disjoint:
+ "finite I ==> (ALL i:I. finite (A i)) ==>
+ (ALL i:I. ALL j:I. i \<noteq> j --> A i Int A j = {}) ==>
+ setprod f (UNION I A) = setprod (%i. setprod f (A i)) I"
+ by (fact setprod.UNION_disjoint)
+
+lemma setprod_Sigma: "finite A ==> ALL x:A. finite (B x) ==>
+ (\<Prod>x\<in>A. (\<Prod>y\<in> B x. f x y)) =
+ (\<Prod>(x,y)\<in>(SIGMA x:A. B x). f x y)"
+ by (fact setprod.Sigma)
+
+lemma setprod_timesf: "setprod (\<lambda>x. f x * g x) A = setprod f A * setprod g A"
+ by (fact setprod.distrib)
+
+
+subsubsection {* Properties in more restricted classes of structures *}
+
+lemma setprod_zero:
+ "finite A ==> EX x: A. f x = (0::'a::comm_semiring_1) ==> setprod f A = 0"
+apply (induct set: finite, force, clarsimp)
+apply (erule disjE, auto)
+done
+
+lemma setprod_zero_iff[simp]: "finite A ==>
+ (setprod f A = (0::'a::{comm_semiring_1,no_zero_divisors})) =
+ (EX x: A. f x = 0)"
+by (erule finite_induct, auto simp:no_zero_divisors)
+
+lemma setprod_Un: "finite A ==> finite B ==> (ALL x: A Int B. f x \<noteq> 0) ==>
+ (setprod f (A Un B) :: 'a ::{field})
+ = setprod f A * setprod f B / setprod f (A Int B)"
+by (subst setprod_Un_Int [symmetric], auto)
+
+lemma setprod_nonneg [rule_format]:
+ "(ALL x: A. (0::'a::linordered_semidom) \<le> f x) --> 0 \<le> setprod f A"
+by (cases "finite A", induct set: finite, simp_all add: mult_nonneg_nonneg)
+
+lemma setprod_pos [rule_format]: "(ALL x: A. (0::'a::linordered_semidom) < f x)
+ --> 0 < setprod f A"
+by (cases "finite A", induct set: finite, simp_all add: mult_pos_pos)
+
+lemma setprod_diff1: "finite A ==> f a \<noteq> 0 ==>
+ (setprod f (A - {a}) :: 'a :: {field}) =
+ (if a:A then setprod f A / f a else setprod f A)"
+ by (erule finite_induct) (auto simp add: insert_Diff_if)
+
+lemma setprod_inversef:
+ fixes f :: "'b \<Rightarrow> 'a::field_inverse_zero"
+ shows "finite A ==> setprod (inverse \<circ> f) A = inverse (setprod f A)"
+by (erule finite_induct) auto
+
+lemma setprod_dividef:
+ fixes f :: "'b \<Rightarrow> 'a::field_inverse_zero"
+ shows "finite A
+ ==> setprod (%x. f x / g x) A = setprod f A / setprod g A"
+apply (subgoal_tac
+ "setprod (%x. f x / g x) A = setprod (%x. f x * (inverse \<circ> g) x) A")
+apply (erule ssubst)
+apply (subst divide_inverse)
+apply (subst setprod_timesf)
+apply (subst setprod_inversef, assumption+, rule refl)
+apply (rule setprod_cong, rule refl)
+apply (subst divide_inverse, auto)
+done
+
+lemma setprod_dvd_setprod [rule_format]:
+ "(ALL x : A. f x dvd g x) \<longrightarrow> setprod f A dvd setprod g A"
+ apply (cases "finite A")
+ apply (induct set: finite)
+ apply (auto simp add: dvd_def)
+ apply (rule_tac x = "k * ka" in exI)
+ apply (simp add: algebra_simps)
+done
+
+lemma setprod_dvd_setprod_subset:
+ "finite B \<Longrightarrow> A <= B \<Longrightarrow> setprod f A dvd setprod f B"
+ apply (subgoal_tac "setprod f B = setprod f A * setprod f (B - A)")
+ apply (unfold dvd_def, blast)
+ apply (subst setprod_Un_disjoint [symmetric])
+ apply (auto elim: finite_subset intro: setprod_cong)
+done
+
+lemma setprod_dvd_setprod_subset2:
+ "finite B \<Longrightarrow> A <= B \<Longrightarrow> ALL x : A. (f x::'a::comm_semiring_1) dvd g x \<Longrightarrow>
+ setprod f A dvd setprod g B"
+ apply (rule dvd_trans)
+ apply (rule setprod_dvd_setprod, erule (1) bspec)
+ apply (erule (1) setprod_dvd_setprod_subset)
+done
+
+lemma dvd_setprod: "finite A \<Longrightarrow> i:A \<Longrightarrow>
+ (f i ::'a::comm_semiring_1) dvd setprod f A"
+by (induct set: finite) (auto intro: dvd_mult)
+
+lemma dvd_setsum [rule_format]: "(ALL i : A. d dvd f i) \<longrightarrow>
+ (d::'a::comm_semiring_1) dvd (SUM x : A. f x)"
+ apply (cases "finite A")
+ apply (induct set: finite)
+ apply auto
+done
+
+lemma setprod_mono:
+ fixes f :: "'a \<Rightarrow> 'b\<Colon>linordered_semidom"
+ assumes "\<forall>i\<in>A. 0 \<le> f i \<and> f i \<le> g i"
+ shows "setprod f A \<le> setprod g A"
+proof (cases "finite A")
+ case True
+ hence ?thesis "setprod f A \<ge> 0" using subset_refl[of A]
+ proof (induct A rule: finite_subset_induct)
+ case (insert a F)
+ thus "setprod f (insert a F) \<le> setprod g (insert a F)" "0 \<le> setprod f (insert a F)"
+ unfolding setprod_insert[OF insert(1,3)]
+ using assms[rule_format,OF insert(2)] insert
+ by (auto intro: mult_mono mult_nonneg_nonneg)
+ qed auto
+ thus ?thesis by simp
+qed auto
+
+lemma abs_setprod:
+ fixes f :: "'a \<Rightarrow> 'b\<Colon>{linordered_field,abs}"
+ shows "abs (setprod f A) = setprod (\<lambda>x. abs (f x)) A"
+proof (cases "finite A")
+ case True thus ?thesis
+ by induct (auto simp add: field_simps abs_mult)
+qed auto
+
+lemma setprod_constant: "finite A ==> (\<Prod>x\<in> A. (y::'a::{comm_monoid_mult})) = y^(card A)"
+apply (erule finite_induct)
+apply auto
+done
+
+lemma setprod_gen_delta:
+ assumes fS: "finite S"
+ shows "setprod (\<lambda>k. if k=a then b k else c) S = (if a \<in> S then (b a ::'a::comm_monoid_mult) * c^ (card S - 1) else c^ card S)"
+proof-
+ let ?f = "(\<lambda>k. if k=a then b k else c)"
+ {assume a: "a \<notin> S"
+ hence "\<forall> k\<in> S. ?f k = c" by simp
+ hence ?thesis using a setprod_constant[OF fS, of c] by simp }
+ moreover
+ {assume a: "a \<in> S"
+ let ?A = "S - {a}"
+ let ?B = "{a}"
+ have eq: "S = ?A \<union> ?B" using a by blast
+ have dj: "?A \<inter> ?B = {}" by simp
+ from fS have fAB: "finite ?A" "finite ?B" by auto
+ have fA0:"setprod ?f ?A = setprod (\<lambda>i. c) ?A"
+ apply (rule setprod_cong) by auto
+ have cA: "card ?A = card S - 1" using fS a by auto
+ have fA1: "setprod ?f ?A = c ^ card ?A" unfolding fA0 apply (rule setprod_constant) using fS by auto
+ have "setprod ?f ?A * setprod ?f ?B = setprod ?f S"
+ using setprod_Un_disjoint[OF fAB dj, of ?f, unfolded eq[symmetric]]
+ by simp
+ then have ?thesis using a cA
+ by (simp add: fA1 field_simps cong add: setprod_cong cong del: if_weak_cong)}
+ ultimately show ?thesis by blast
+qed
+
+lemma setprod_eq_1_iff [simp]:
+ "finite F ==> setprod f F = 1 \<longleftrightarrow> (ALL a:F. f a = (1::nat))"
+ by (induct set: finite) auto
+
+lemma setprod_pos_nat:
+ "finite S ==> (ALL x : S. f x > (0::nat)) ==> setprod f S > 0"
+using setprod_zero_iff by(simp del:neq0_conv add:neq0_conv[symmetric])
+
+lemma setprod_pos_nat_iff[simp]:
+ "finite S ==> (setprod f S > 0) = (ALL x : S. f x > (0::nat))"
+using setprod_zero_iff by(simp del:neq0_conv add:neq0_conv[symmetric])
+
+end
--- a/src/HOL/Hilbert_Choice.thy Sat Dec 14 20:46:36 2013 +0100
+++ b/src/HOL/Hilbert_Choice.thy Sun Dec 15 15:10:14 2013 +0100
@@ -6,7 +6,7 @@
header {* Hilbert's Epsilon-Operator and the Axiom of Choice *}
theory Hilbert_Choice
-imports Nat Wellfounded Big_Operators
+imports Nat Wellfounded Lattices_Big Metis
keywords "specification" "ax_specification" :: thy_goal
begin
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Lattices_Big.thy Sun Dec 15 15:10:14 2013 +0100
@@ -0,0 +1,833 @@
+(* Title: HOL/Lattices_Big.thy
+ Author: Tobias Nipkow, Lawrence C Paulson and Markus Wenzel
+ with contributions by Jeremy Avigad
+*)
+
+header {* Big infimum (minimum) and supremum (maximum) over finite (non-empty) sets *}
+
+theory Lattices_Big
+imports Finite_Set
+begin
+
+subsection {* Generic lattice operations over a set *}
+
+no_notation times (infixl "*" 70)
+no_notation Groups.one ("1")
+
+
+subsubsection {* Without neutral element *}
+
+locale semilattice_set = semilattice
+begin
+
+interpretation comp_fun_idem f
+ by default (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 default (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 * F A"
+proof -
+ from `A \<noteq> {}` 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 `finite A` and `x \<notin> A`
+ have "finite (insert x B)" and "b \<notin> insert x B" by auto
+ then have "F (insert b (insert x B)) = x * 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 * F A = F A"
+proof -
+ from assms have "A \<noteq> {}" by auto
+ with `finite A` show ?thesis using `x \<in> A`
+ 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 * 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 * 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 * 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 * 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 * 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 * y \<in> {x, y}"
+ shows "F A \<in> A"
+using `finite A` `A \<noteq> {}` 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 * y) = h x * 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 * F N)" by simp
+ also have "\<dots> = h n * h (F N)" by (rule hom)
+ also have "h (F N) = F (h ` N)" by (rule insert)
+ also have "h n * \<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
+
+end
+
+locale semilattice_order_set = semilattice_order + semilattice_set
+begin
+
+lemma bounded_iff:
+ assumes "finite A" and "A \<noteq> {}"
+ shows "x \<preceq> F A \<longleftrightarrow> (\<forall>a\<in>A. x \<preceq> a)"
+ using assms by (induct rule: finite_ne_induct) (simp_all add: bounded_iff)
+
+lemma boundedI:
+ assumes "finite A"
+ assumes "A \<noteq> {}"
+ assumes "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
+ shows "x \<preceq> F A"
+ using assms by (simp add: bounded_iff)
+
+lemma boundedE:
+ assumes "finite A" and "A \<noteq> {}" and "x \<preceq> F A"
+ obtains "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
+ using assms by (simp add: bounded_iff)
+
+lemma coboundedI:
+ assumes "finite A"
+ and "a \<in> A"
+ shows "F A \<preceq> a"
+proof -
+ from assms have "A \<noteq> {}" by auto
+ from `finite A` `A \<noteq> {}` `a \<in> A` 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 antimono:
+ assumes "A \<subseteq> B" and "A \<noteq> {}" and "finite B"
+ shows "F B \<preceq> 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 `A \<subseteq> B` by blast
+ then have "F B = F (A \<union> (B - A))" by simp
+ also have "\<dots> = F A * F (B - A)" using False assms by (subst union) (auto intro: finite_subset)
+ also have "\<dots> \<preceq> F A" by simp
+ finally show ?thesis .
+qed
+
+end
+
+
+subsubsection {* With neutral element *}
+
+locale semilattice_neutr_set = semilattice_neutr
+begin
+
+interpretation comp_fun_idem f
+ by default (simp_all add: fun_eq_iff left_commute)
+
+definition F :: "'a set \<Rightarrow> 'a"
+where
+ eq_fold: "F A = Finite_Set.fold f 1 A"
+
+lemma infinite [simp]:
+ "\<not> finite A \<Longrightarrow> F A = 1"
+ by (simp add: eq_fold)
+
+lemma empty [simp]:
+ "F {} = 1"
+ by (simp add: eq_fold)
+
+lemma insert [simp]:
+ assumes "finite A"
+ shows "F (insert x A) = x * F A"
+ using assms by (simp add: eq_fold)
+
+lemma in_idem:
+ assumes "finite A" and "x \<in> A"
+ shows "x * F A = F A"
+proof -
+ from assms have "A \<noteq> {}" by auto
+ with `finite A` show ?thesis using `x \<in> A`
+ 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 * 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 * 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 * 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 * 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 * y \<in> {x, y}"
+ shows "F A \<in> A"
+using `finite A` `A \<noteq> {}` 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 = semilattice_neutr_order + semilattice_neutr_set
+begin
+
+lemma bounded_iff:
+ assumes "finite A"
+ shows "x \<preceq> F A \<longleftrightarrow> (\<forall>a\<in>A. x \<preceq> a)"
+ using assms by (induct A) (simp_all add: bounded_iff)
+
+lemma boundedI:
+ assumes "finite A"
+ assumes "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
+ shows "x \<preceq> F A"
+ using assms by (simp add: bounded_iff)
+
+lemma boundedE:
+ assumes "finite A" and "x \<preceq> F A"
+ obtains "\<And>a. a \<in> A \<Longrightarrow> x \<preceq> a"
+ using assms by (simp add: bounded_iff)
+
+lemma coboundedI:
+ assumes "finite A"
+ and "a \<in> A"
+ shows "F A \<preceq> a"
+proof -
+ from assms have "A \<noteq> {}" by auto
+ from `finite A` `A \<noteq> {}` `a \<in> A` 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 antimono:
+ assumes "A \<subseteq> B" and "finite B"
+ shows "F B \<preceq> 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 `A \<subseteq> B` by blast
+ then have "F B = F (A \<union> (B - A))" by simp
+ also have "\<dots> = F A * F (B - A)" using False assms by (subst union) (auto intro: finite_subset)
+ also have "\<dots> \<preceq> F A" by simp
+ finally show ?thesis .
+qed
+
+end
+
+notation times (infixl "*" 70)
+notation Groups.one ("1")
+
+
+subsection {* Lattice operations on finite sets *}
+
+text {*
+ For historic reasons, there is the sublocale dependency from @{class distrib_lattice}
+ to @{class linorder}. This is badly designed: both should depend on a common abstract
+ distributive lattice rather than having this non-subclass dependecy between two
+ classes. But for the moment we have to live with it. This forces us to setup
+ this sublocale dependency simultaneously with the lattice operations on finite
+ sets, to avoid garbage.
+*}
+
+definition (in semilattice_inf) Inf_fin :: "'a set \<Rightarrow> 'a" ("\<Sqinter>\<^sub>f\<^sub>i\<^sub>n_" [900] 900)
+where
+ "Inf_fin = semilattice_set.F inf"
+
+definition (in semilattice_sup) Sup_fin :: "'a set \<Rightarrow> 'a" ("\<Squnion>\<^sub>f\<^sub>i\<^sub>n_" [900] 900)
+where
+ "Sup_fin = semilattice_set.F sup"
+
+context linorder
+begin
+
+definition Min :: "'a set \<Rightarrow> 'a"
+where
+ "Min = semilattice_set.F min"
+
+definition Max :: "'a set \<Rightarrow> 'a"
+where
+ "Max = semilattice_set.F max"
+
+sublocale Min!: semilattice_order_set min less_eq less
+ + Max!: semilattice_order_set max greater_eq greater
+where
+ "semilattice_set.F min = Min"
+ and "semilattice_set.F max = Max"
+proof -
+ show "semilattice_order_set min less_eq less" by default (auto simp add: min_def)
+ then interpret Min!: semilattice_order_set min less_eq less .
+ show "semilattice_order_set max greater_eq greater" by default (auto simp add: max_def)
+ then interpret Max!: semilattice_order_set max greater_eq greater .
+ from Min_def show "semilattice_set.F min = Min" by rule
+ from Max_def show "semilattice_set.F max = Max" by rule
+qed
+
+
+text {* An aside: @{const min}/@{const max} on linear orders as special case of @{const inf}/@{const sup} *}
+
+sublocale min_max!: distrib_lattice min less_eq less max
+where
+ "semilattice_inf.Inf_fin min = Min"
+ and "semilattice_sup.Sup_fin max = Max"
+proof -
+ show "class.distrib_lattice min less_eq less max"
+ proof
+ fix x y z
+ show "max x (min y z) = min (max x y) (max x z)"
+ by (auto simp add: min_def max_def)
+ qed (auto simp add: min_def max_def not_le less_imp_le)
+ then interpret min_max!: distrib_lattice min less_eq less max .
+ show "semilattice_inf.Inf_fin min = Min"
+ by (simp only: min_max.Inf_fin_def Min_def)
+ show "semilattice_sup.Sup_fin max = Max"
+ by (simp only: min_max.Sup_fin_def Max_def)
+qed
+
+lemmas le_maxI1 = min_max.sup_ge1
+lemmas le_maxI2 = min_max.sup_ge2
+
+lemmas min_ac = min_max.inf_assoc min_max.inf_commute
+ min.left_commute
+
+lemmas max_ac = min_max.sup_assoc min_max.sup_commute
+ max.left_commute
+
+end
+
+
+text {* Lattice operations proper *}
+
+sublocale semilattice_inf < Inf_fin!: semilattice_order_set inf less_eq less
+where
+ "semilattice_set.F inf = Inf_fin"
+proof -
+ show "semilattice_order_set inf less_eq less" ..
+ then interpret Inf_fin!: semilattice_order_set inf less_eq less .
+ from Inf_fin_def show "semilattice_set.F inf = Inf_fin" by rule
+qed
+
+sublocale semilattice_sup < Sup_fin!: semilattice_order_set sup greater_eq greater
+where
+ "semilattice_set.F sup = Sup_fin"
+proof -
+ show "semilattice_order_set sup greater_eq greater" ..
+ then interpret Sup_fin!: semilattice_order_set sup greater_eq greater .
+ from Sup_fin_def show "semilattice_set.F sup = Sup_fin" by rule
+qed
+
+
+text {* An aside again: @{const Min}/@{const Max} on linear orders as special case of @{const Inf_fin}/@{const Sup_fin} *}
+
+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)
+
+
+
+subsection {* Infimum and Supremum over non-empty sets *}
+
+text {*
+ After this non-regular bootstrap, things continue canonically.
+*}
+
+context lattice
+begin
+
+lemma Inf_le_Sup [simp]: "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> \<Sqinter>\<^sub>f\<^sub>i\<^sub>nA \<le> \<Squnion>\<^sub>f\<^sub>i\<^sub>nA"
+apply(subgoal_tac "EX a. a:A")
+prefer 2 apply blast
+apply(erule exE)
+apply(rule order_trans)
+apply(erule (1) Inf_fin.coboundedI)
+apply(erule (1) Sup_fin.coboundedI)
+done
+
+lemma sup_Inf_absorb [simp]:
+ "finite A \<Longrightarrow> a \<in> A \<Longrightarrow> sup a (\<Sqinter>\<^sub>f\<^sub>i\<^sub>nA) = a"
+apply(subst sup_commute)
+apply(simp add: sup_absorb2 Inf_fin.coboundedI)
+done
+
+lemma inf_Sup_absorb [simp]:
+ "finite A \<Longrightarrow> a \<in> A \<Longrightarrow> inf a (\<Squnion>\<^sub>f\<^sub>i\<^sub>nA) = a"
+by (simp add: inf_absorb1 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} = (UN a:A. UN b: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} = (UN a:A. UN b: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 = Inf 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 = Sup 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 {* Minimum and Maximum over non-empty sets *}
+
+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_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 `x \<in> A` 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 `x \<in> A` 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
+
+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 Min_antimono:
+ assumes "M \<subseteq> N" and "M \<noteq> {}" and "finite N"
+ shows "Min N \<le> Min M"
+ using assms by (fact Min.antimono)
+
+lemma Max_mono:
+ assumes "M \<subseteq> N" and "M \<noteq> {}" and "finite N"
+ shows "Max M \<le> Max N"
+ using assms by (fact Max.antimono)
+
+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 `finite A` 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 `mono f` have "f (Min A) \<le> f y" by (rule monoE)
+ with `x = f y` 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 `finite A` 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 `mono f` have "f y \<le> f (Max A)" by (rule monoE)
+ with `x = f y` 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 `P {}` by simp
+ next
+ let ?B = "A - {Max A}"
+ let ?A = "insert (Max A) ?B"
+ have "finite ?B" using `finite A` by simp
+ assume "A \<noteq> {}"
+ with `finite A` have "Max A : A" by auto
+ then have A: "?A = A" using insert_Diff_single insert_absorb by auto
+ then have "P ?B" using `P {}` step IH [of ?B] by blast
+ moreover
+ have "\<forall>a\<in>?B. a < Max A" using Max_ge [OF `finite A`] by fastforce
+ ultimately show "P A" using A insert_Diff_single step [OF `finite ?B`] 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 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
+
+end
+
+context linordered_ab_semigroup_add
+begin
+
+lemma add_Min_commute:
+ fixes k
+ assumes "finite N" and "N \<noteq> {}"
+ shows "k + Min N = Min {k + m | m. m \<in> N}"
+proof -
+ have "\<And>x y. k + min x y = min (k + x) (k + y)"
+ by (simp add: min_def not_le)
+ (blast intro: antisym less_imp_le add_left_mono)
+ with assms show ?thesis
+ using hom_Min_commute [of "plus k" N]
+ by simp (blast intro: arg_cong [where f = Min])
+qed
+
+lemma add_Max_commute:
+ fixes k
+ assumes "finite N" and "N \<noteq> {}"
+ shows "k + Max N = Max {k + m | m. m \<in> N}"
+proof -
+ have "\<And>x y. k + max x y = max (k + x) (k + y)"
+ by (simp add: max_def not_le)
+ (blast intro: antisym less_imp_le add_left_mono)
+ with assms show ?thesis
+ using hom_Max_commute [of "plus k" N]
+ by simp (blast intro: arg_cong [where f = Max])
+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
+
+end