"Normal lists have O(1) cons, head, and tail operations, but looking up an element by subscript n takes n operations. With a data structure based on skew binary numbers, we can retain O(1) complexity for list operations, and permit lookup and update operations by subscript with O(log n) complexity. The idea is to have a skew binary list, where each position holds a binary tree with as many elements as the weight of that position."
- Lindsey Kuper