diff -r aa2deef7cf47 -r ebd8ecacfba6 src/HOL/Library/Convex.thy
--- a/src/HOL/Library/Convex.thy Wed Feb 18 22:46:48 2015 +0100
+++ b/src/HOL/Library/Convex.thy Thu Feb 19 11:53:36 2015 +0100
@@ -329,7 +329,7 @@
have "u * f x + v * f y \ u * max (f x) (f y) + v * max (f x) (f y)"
using assms(4,5) by (auto simp add: mult_left_mono add_mono)
also have "\ = max (f x) (f y)"
- using assms(6) unfolding distrib[symmetric] by auto
+ using assms(6) by (simp add: distrib_right [symmetric])
finally show ?thesis
using assms unfolding convex_on_def by fastforce
qed