On Apr 9, 2009, at 5:50 PM, Todd O'Bryan wrote: > (make-Cons 5 (make-Cons 3 (make-Cons 2 (make-Empty)))) Try 5.0 or 3.0 or 2.0. You won't need all of them. Apparently (Listof Integer) < (Listof Number). Hmph. -- Matthias