--- a/src/Pure/envir.ML Sat Nov 08 16:55:41 2014 +0100
+++ b/src/Pure/envir.ML Sat Nov 08 17:39:01 2014 +0100
@@ -124,7 +124,7 @@
and use = instead of eq_type.*)
fun lookup1 tenv = lookup_check (op =) tenv;
-fun lookup (Envir {tenv, tyenv, ...}) = lookup_check (Type.eq_type tyenv) tenv;
+fun lookup (Envir {tenv, tyenv, ...}) = lookup_check (Type.unified tyenv) tenv;
fun update ((xi, T), t) (Envir {maxidx, tenv, tyenv}) =
Envir {maxidx = maxidx, tenv = Vartab.update_new (xi, (T, t)) tenv, tyenv = tyenv};