> One could absolutely use a Dequeue or some other optimized structure for a Lisp list How? With naked deque nodes? Since otherwise you wouldn't get Lisp lists

> One could absolutely use a Dequeue or some other optimized structure for a Lisp list How? With naked deque nodes? Since otherwise you wouldn't get Lisp lists, you couldn't have structure sharing, etc. And where would the reverse deque node pointer point to if multiple nodes pointed to the node in question?