Sign.base_name;

--- a/src/Pure/section_utils.ML	Mon Oct 20 10:39:04 1997 +0200
+++ b/src/Pure/section_utils.ML	Mon Oct 20 10:39:26 1997 +0200
@@ -16,7 +16,7 @@
 (*Make a definition lhs==rhs*)
 fun mk_defpair (lhs, rhs) = 
   let val Const(name, _) = head_of lhs
-  in (name ^ "_def", Logic.mk_equals (lhs, rhs)) end;
+  in (Sign.base_name name ^ "_def", Logic.mk_equals (lhs, rhs)) end;
 
 fun get_def thy s = get_axiom thy (s^"_def");