(define :+ +)
(define (+ a b)
   (if (vector? a)
      (if (vector? b)
         (vector-map :+ a b)
         (error "error:" "not applicable (+ vector non-vector)"))
      (if (vector? b)
         (error "error:" "not applicable (+ non-vector vector)")
         (:+ a b))))

(define :- -)
(define (- a b)
   (if (vector? a)
      (if (vector? b)
         (vector-map :- a b)
         (error "error:" "not applicable (+ vector non-vector)"))
      (if (vector? b)
         (error "error:" "not applicable (+ non-vector vector)")
         (:- a b))))

(define :* *)
(define (* a b)
   (if (vector? a)
      (if (not (vector? b))
         (vector-map (lambda (x) (:* x b)) a)
         (error "error:" "not applicable (* vector vector)"))
      (if (vector? b)
         (error "error:" "not applicable (* scalar vector)")
         (:* a b))))

(define :/ /)
(define (/ a b)
   (if (vector? a)
      (if (not (vector? b))
         (vector-map (lambda (x) (:/ x b)) a)
         (error "error:" "not applicable (/ vector vector)"))
      (if (vector? b)
         (error "error:" "not applicable (/ scalar vector)")
         (:/ a b))))

(define x [1 2 3 4 5])
(define y [7 8 5 4 2])
(print x " + " y " = " (+ x y))
(print x " - " y " = " (- x y))
(print x " * " 7 " = " (* x 7))
(print x " / " 7 " = " (/ x 7))