(defun C+ (x y)
  (cons (+ (car x) (car y)) (+ (cdr x) (cdr y))))

(defun C- (x y)
  (cons (- (car x) (car y)) (+ (cdr x) (cdr y))))

(defun CC (x)
  (cons (car x) (- (cdr x))))

(defun c* (x y)
  (cons (- (* (car x) (car y))
	   (* (cdr x) (cdr y)))
	(+ (* (car x) (cdr y))
	   (* (cdr x) (car y)))))