NEWS

--- a/NEWS	Sun Dec 27 16:40:09 2015 +0100
+++ b/NEWS	Sun Dec 27 17:16:21 2015 +0100
@@ -474,6 +474,8 @@
 The subsequent commands help to reproduce the old forms, e.g. to
 simplify porting old theories:
 
+  notation iff  (infixr "<->" 25)
+
   type_notation Map.map  (infixr "~=>" 0)
   notation Map.map_comp  (infixl "o'_m" 55)