ones = 1 : ones 

lotsa x = x : (lotsa x)

silly i = (i+1) : (silly i)

kernel n =  n : (kernel (n+1))

natural = kernel 0

square x = x * x

select pred (x:xs) = iif (pred x) (x : (select pred xs)) (select pred xs)

odd x = (mod x 2) == 1