---

Implement

… in Scheme as

• my-vector-subtract

  (define (my-vector-subtract vector . vectors)
    (if (null? vectors)
        vector
        (my-vector-add vector
                       (my-vector-additive-inverse
                        (apply my-vector-subtract
                               vectors)))))
  

  in terms of my-vector-add.

• my-vector-additive-inverse

  (define (my-vector-additive-inverse vector)
    (my-vector-scale vector -1))
  

  in terms of my-vector-scale.