gistfile1.txt

gosh> (define (foo ls)
        (if (null? ls)
          '(0)
          (map + ls (append (foo (cdr ls)) '(0)))))
foo
gosh> (foo '(1 2 3))
(6 5 3)

;;    1 2 3
;;    2 3 0
;;  + 3 0 0
;;   ------
;;    6 5 3