diff -r b47d41d9f4b5 -r 6ca5407863ed src/Pure/display.ML
--- a/src/Pure/display.ML	Sat Apr 16 13:48:45 2011 +0200
+++ b/src/Pure/display.ML	Sat Apr 16 15:25:25 2011 +0200
@@ -195,7 +195,7 @@
 
     val clsses = Name_Space.dest_table ctxt (class_space, Symtab.make (Graph.dest classes));
     val tdecls = Name_Space.dest_table ctxt types;
-    val arties = Name_Space.dest_table ctxt (Sign.type_space thy, arities);
+    val arties = Name_Space.dest_table ctxt (Type.type_space tsig, arities);
 
     fun prune_const c = not verbose andalso Consts.is_concealed consts c;
     val cnsts = Name_Space.extern_table ctxt (#1 constants,