adapted Name.defaults_of;

--- a/src/Pure/Isar/proof_context.ML	Tue Jul 11 23:00:37 2006 +0200
+++ b/src/Pure/Isar/proof_context.ML	Tue Jul 11 23:00:39 2006 +0200
@@ -1247,7 +1247,7 @@
     val prt_defT = prt_atom prt_var prt_typ;
     val prt_defS = prt_atom prt_varT prt_sort;
 
-    val (types, sorts, used, _, _) = Variable.defaults_of ctxt;
+    val (types, sorts, used, _) = Variable.defaults_of ctxt;
   in
     verb single (K pretty_thy) @
     pretty_ctxt ctxt @