Function: FIND-TRIE

Source

(defun find-trie (key extend? trie)
  (cond ((null trie) nil)
	((atom key)
	 (follow-arc key extend? trie))
	(t (find-trie (cdr key) extend?
		      (find-trie (car key) extend?
				 (find-trie "." extend? trie))))))