;; merge two ORDDERED lists OF NUMBERS
(define (merge list1 list2)
   (cond ((null? list1) list2) 
         ((null? list2) list1)
         ((< (car list1)(car list2))
          (cons (car list1)(merge (cdr list1) list2)))
         (#t (cons (car list2)(merge list1 (cdr list2))))))

(merge (list 1 3 5)(list 2 4))

(merge (list)(list 1 2))