list a ::= Nil | Cons a (list a);

;;

if c t f = case c of True -> t; False -> f end;

loses l = case l of Nil -> 0; Cons x xs -> 1 + loses xs end;

gains x = letrec loop=loop in loop;

rep n x = if (n <= 0) Nil (Cons x (rep (n-1) x));

length = loses;

append l1 l2 = case l1 of Nil -> l2; Cons x xs -> Cons x (append xs l2) end;

gainAndLose as bs 
   = letrec loop=loop in append as (rep (length bs) loop);