src/HOL/Analysis/Brouwer_Fixpoint.thy
changeset 73466 ee1c4962671c
parent 72569 d56e4eeae967
child 73648 1bd3463e30b8
--- a/src/HOL/Analysis/Brouwer_Fixpoint.thy	Mon Mar 22 00:07:55 2021 +0100
+++ b/src/HOL/Analysis/Brouwer_Fixpoint.thy	Mon Mar 22 10:49:51 2021 +0000
@@ -234,11 +234,6 @@
     by auto
 qed
 
-lemma swap_image:
-  "Fun.swap i j f ` A = (if i \<in> A then (if j \<in> A then f ` A else f ` ((A - {i}) \<union> {j}))
-                                  else (if j \<in> A then f ` ((A - {j}) \<union> {i}) else f ` A))"
-  by (auto simp: swap_def cong: image_cong_simp)
-
 lemmas swap_apply1 = swap_apply(1)
 lemmas swap_apply2 = swap_apply(2)
 
@@ -2598,5 +2593,4 @@
   using derf has_derivative_continuous by blast
 qed (use assms in auto)
 
-
 end