diff -r 7ff7fdfbb9a0 -r 58e5b16cbd94 src/HOL/Library/Rewrite.thy
--- a/src/HOL/Library/Rewrite.thy	Mon Apr 13 00:59:17 2015 +0200
+++ b/src/HOL/Library/Rewrite.thy	Mon Apr 13 10:21:35 2015 +0200
@@ -10,7 +10,7 @@
 
 consts rewrite_HOLE :: "'a::{}"
 notation rewrite_HOLE ("HOLE")
-notation rewrite_HOLE ("\<box>")
+notation rewrite_HOLE ("\<hole>")
 
 lemma eta_expand:
   fixes f :: "'a::{} \<Rightarrow> 'b::{}"