diff -r 143f58bb34f9 -r 0909deb8059b src/HOL/Imperative_HOL/ex/Subarray.thy
--- a/src/HOL/Imperative_HOL/ex/Subarray.thy	Thu May 26 16:57:14 2016 +0200
+++ b/src/HOL/Imperative_HOL/ex/Subarray.thy	Thu May 26 17:51:22 2016 +0200
@@ -2,7 +2,7 @@
     Author:     Lukas Bulwahn, TU Muenchen
 *)
 
-section {* Theorems about sub arrays *}
+section \<open>Theorems about sub arrays\<close>
 
 theory Subarray
 imports "~~/src/HOL/Imperative_HOL/Array" List_Sublist