obj X =  any;
obj Y =  x:X;
obj Z =  X;
obj W =  Z;

op f(y:Y, z:Z);
  (* ^^^^^^^^ Problem here is that Z is said to be undefined, but Y isnt.  This
   *          is evidently due to the one-tuple wrapper that's put around Y.
   * **NOTE**: The problem is no longer *)

op g(w:W);
  (* ^^^ W shows as undef'd as well.  Hmm. *)