;;; $Id: sum.scm,v 1.2 2002/04/09 22:25:25 leavens Exp $

(define sum
  (lambda args
    (sum-of-list args)))

(define sum-of-list
  (lambda (lon)
    (if (null? lon)
	0
	(+ (car lon)
	   (sum-of-list (cdr lon))))))