>=20 > I don't think so. I think it only takes linear time to get the head. > But once you've gotten the head, it takes linear time again to get the > head of the tail, .... You get (I think...) a progression like > n+(n-1)+(n-2)+...+1, which is in O(n^2). >=20 What does 'n' denote? The get the head, it takes time proportional to the number of (++) invocations. Is that what you mean? konst