diff -r ada832308efe -r 12a89103cae6 src/Pure/variable.ML
--- a/src/Pure/variable.ML	Tue Mar 31 19:39:05 2015 +0200
+++ b/src/Pure/variable.ML	Tue Mar 31 20:07:37 2015 +0200
@@ -347,7 +347,7 @@
 
 (* specialized name space *)
 
-val is_fixed = Name_Space.defined_entry o fixes_space;
+val is_fixed = Name_Space.defined o fixes_of;
 fun is_newly_fixed inner outer = is_fixed inner andf (not o is_fixed outer);
 
 val fixed_ord = Name_Space.entry_ord o fixes_space;