(define (derivative xs)
  (cond ((equal? xs 'x) 1)
        ((number? xs) 0)
        ((equal? (car xs) 'expt)
         (cond
           ((equal? (cadr xs) 'x )
            (let* ((arg (cadr xs)) (pow (caddr xs)))
               (list '* pow (list 'expt arg (- pow 1)))))
           ((and (number? (cadr xs)) (equal? (caddr xs) 'x))
            (let* ((arg (cadr xs)) (pow (caddr xs)))
               (list '* (list 'expt arg pow) (list 'log arg))))
           ((number? (cadr xs))
            (let* ((arg (cadr xs)) (pow (caddr xs)))
               (list '* (list 'expt arg pow) (list 'log arg) (derivative arg))))
           ((and (not (number? (cadr xs))) (not (equal? (cadr xs) 'exp)))
               (let* ((arg (cadr xs)) (pow (caddr xs)))
                 (list '* pow (list 'expt arg (- pow 1)) (derivative arg))))))
        ((equal? (car xs) 'sin) (list '* (list 'cos (cadr xs)) (derivative (cadr xs))))
        ((equal? (car xs) 'cos) (list '- (list '* (list 'sin (cadr xs)) (derivative (cadr xs)))))
        ((equal? (car xs) '*)
         (cond
           ((and (number? (cadr xs)) (equal? (caddr xs) 'x)) (cadr xs))
           ((and (number? (cadr xs)) (not (> (length xs) 3))) (list '* (cadr xs) (derivative (caddr xs))))
           ((and (number? (cadr xs)) (number? (caddr xs))) 0)
           ((> (length xs) 3)
                (list '+ (list '* (derivative (cadr xs)) (caddr xs) (cadddr xs)) (list '* (cadr xs) (derivative (caddr xs)) (cadddr xs))
                      (list '* (cadr xs) (caddr xs) (derivative (cadddr xs)))))
           (else
           (list '+ (list '* (derivative (cadr xs)) (caddr xs)) (list '* (cadr xs) (derivative (caddr xs)))))))
        ((equal? (car xs) '+) (list '+ (derivative (cadr xs)) (derivative (caddr xs))))
        ((equal? (car xs) '-)
         (if (not (equal? (length xs) 3))
             -1
             (list '- (derivative (cadr xs)) (derivative (caddr xs)))))
        ((equal? (car xs) '/)
         (cond
           ((and (number? (cadr xs)) (equal? (caddr xs) 'x)) (list '* '-1 (list '/ (cadr xs) (list 'expt (caddr xs) '2))))
           ((number? (cadr xs)) (list '* '-1 (list '/ (cadr xs) (list 'expt (caddr xs) '2)) (derivative (caddr xs))))
           ((and (number? (cadr xs)) (number? (caddr xs))) 0 )
           (else
            (list '/ (list '- (list '* (derivative (cadr xs)) (caddr xs)) (list '* (cadr xs) (derivative (caddr xs)))) (list 'expt (caddr xs) 2)))))
        ((and (equal? (cadr xs) 'x) (equal? (car xs) 'exp)) (list 'exp 'x))
        ((and (equal? (car xs) 'exp) (not (number? (cadr xs)))) (list '* (list 'exp (cadr xs)) (derivative (cadr xs))))
        ((and (equal? (car xs) 'exp) (number? (cadr xs))) 0)
        ((and (equal? (car xs) 'log) (equal? (cadr xs) 'x)) (list '/ 1 (cadr xs)))
        ((and (equal? (car xs) 'log) (number? (cadr xs))) 0)
        ((and (equal? (car xs) 'log) (not (number? (cadr xs)))) (list '* (list '/ 1 (cadr xs)) (derivative (cadr xs))))))

(begin (define x 2.0) (round (eval (derivative (quote (* 2 (* (exp x) (sin x) (cos x))))) (interaction-environment))))