1 2 3 4 5 6 7 8
;(mod (tree) ; (defun sum (tree) ; (if (l tree) (+ (sum (f tree)) (sum (r tree))) tree) ; ) ; (sum tree) ;) (a (q 2 2 (c 2 (c 5 (q)))) (c (q 2 (i (l 5) (q 16 (a 2 (c 2 (c 9 (q)))) (a 2 (c 2 (c 13 (q))))) (q . 5)) 1) 1))