(wdr (cdr shdr))

(define (bang n)
(if (= n 0)
1
(* n (bang (- n 1)))))

;problem 1
(define (e n);n for depth to calculate e as 1 + 1/2! + 1/3! ...
(if (= n 0)
1
(+ (/ 1 (bang n)) (e (- n 1)))))