src/Pure/Syntax/syntax.ML

--- a/src/Pure/Syntax/syntax.ML	Thu Mar 14 16:40:18 1996 +0100
+++ b/src/Pure/Syntax/syntax.ML	Fri Mar 15 12:01:19 1996 +0100
@@ -308,7 +308,7 @@
     fun show_pt pt = writeln (str_of_ast (pt_to_ast (K None) pt));
   in
     if length pts > ! ambiguity_level then
-      (writeln ("Warning: Ambiguous input " ^ quote str);
+      (warning ("Ambiguous input " ^ quote str);
        writeln "produces the following parse trees:";
        seq show_pt pts)
     else ();