src/Pure/Isar/class.ML
changeset 36746 6e7704471eaa
parent 36745 403585a89772
child 36904 3e200347a22e
--- a/src/Pure/Isar/class.ML	Sat May 08 19:14:13 2010 +0200
+++ b/src/Pure/Isar/class.ML	Sat May 08 19:18:28 2010 +0200
@@ -202,7 +202,7 @@
       |> Expression.cert_declaration supexpr I inferred_elems;
     fun check_vars e vs = if null vs
       then error ("No type variable in part of specification element "
-        ^ (Pretty.output NONE o Pretty.chunks) (Element.pretty_ctxt class_ctxt e))
+        ^ (Pretty.string_of o Pretty.chunks) (Element.pretty_ctxt class_ctxt e))
       else ();
     fun check_element (e as Element.Fixes fxs) =
           map (fn (_, SOME T, _) => check_vars e (Term.add_tfreesT T [])) fxs