added lemmas
authornipkow
Mon, 08 Feb 2021 19:48:45 +0100
changeset 73221 b1aa641eee4c
parent 73220 6974bca47856
child 73238 180ecdf83bc8
added lemmas
src/HOL/Lattices_Big.thy
--- a/src/HOL/Lattices_Big.thy	Mon Feb 01 16:03:07 2021 +0100
+++ b/src/HOL/Lattices_Big.thy	Mon Feb 08 19:48:45 2021 +0100
@@ -560,6 +560,12 @@
   ultimately show ?thesis by (simp add: max.absorb1)
 qed
 
+lemma Max_const[simp]: "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> Max ((\<lambda>_. c) ` A) = c"
+using Max_in image_is_empty by blast
+
+lemma Min_const[simp]: "\<lbrakk> finite A; A \<noteq> {} \<rbrakk> \<Longrightarrow> Min ((\<lambda>_. c) ` A) = c"
+using Min_in image_is_empty by blast
+
 lemma Min_le [simp]:
   assumes "finite A" and "x \<in> A"
   shows "Min A \<le> x"
@@ -671,6 +677,12 @@
 
 end
 
+lemma sum_le_card_Max: "finite A \<Longrightarrow> sum f A \<le> card A * Max (f ` A)"
+using sum_bounded_above[of A f "Max (f ` A)"] by simp
+
+lemma card_Min_le_sum: "finite A \<Longrightarrow> card A * Min (f ` A) \<le> sum f A"
+using sum_bounded_below[of A "Min (f ` A)" f] by simp
+
 context linorder  (* FIXME *)
 begin