;; The first three lines of this file were inserted by DrScheme. They record metadata
;; about the language level of this file in a form that our tools can easily process.
#reader(lib "htdp-intermediate-reader.ss" "lang")((modname 17.6.1) (read-case-sensitive #t) (teachpacks ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "dir.ss" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "dir.ss" "teachpack" "htdp")))))
;A list-of-numbers (lon) is either
;1. empty or
;2. (cons n lon)
;where n is a number and lon is a list-of-numbers (lon).
;
;merge : lon lon -> lon
;Given lon1 and lon2, both lists-of-numbers arranged in ascending order, merge combines the two lists in ascending order and returns the list-of-numbers.

(define (merge lon1 lon2)
  (cond
    [(and (empty? lon1)
          (empty? lon2)) empty]
    [(and (cons? lon1)
          (empty? lon2)) lon1]
    [(and (empty? lon1)
          (cons? lon2)) lon2]
    [(<= (first lon1) (first lon2)) (cons (first lon1)
                                         (merge (rest lon1) lon2))]
    [(> (first lon1) (first lon2)) (cons (first lon2)
                                         (merge lon1 (rest lon2)))]))

(define list-1 '(1 3 5 7 9 21 23 25 27 29 31))
(define list-2 '(2 4 6 8 10 12 14 16))