adamc@238: datatype list a = Nil | Cons of a * list a
adamc@238: 
adamc@238: val rec append : t ::: Type -> list t -> list t -> list t = fn t ::: Type => fn ls1 => fn ls2 =>
adamc@238:         case ls1 of
adamc@238:             Nil => ls2
adamc@238:           | Cons (h, t) => Cons (h, append t ls2)
adamc@238: 
adamc@238: (*val rec ones : list int = Cons (1, ones)*)
adamc@238: val rec ones : unit -> list int = fn () => Cons (1, ones ())