src/HOL/Library/Preorder.thy

--- a/src/HOL/Library/Preorder.thy	Fri Oct 09 19:51:20 2015 +0200
+++ b/src/HOL/Library/Preorder.thy	Fri Oct 09 20:26:03 2015 +0200
@@ -20,10 +20,6 @@
   equiv ("op \<approx>") and
   equiv ("(_/ \<approx> _)"  [51, 51] 50)
 
-notation (HTML output)
-  equiv ("op \<approx>") and
-  equiv ("(_/ \<approx> _)"  [51, 51] 50)
-
 lemma refl [iff]:
   "x \<approx> x"
   unfolding equiv_def by simp