INSERT/INSERTSORT

(define (insert xs n)
  (cond [(null? xs) (cons n null)]
        [(< n (car xs)) (cons n xs)]
        [else (cons (car xs) (insert (cdr xs) n))]))

(define (insert-sort xs)
  (if (null? xs)
      null
      (insert (insert-sort (cdr xs)) (car xs))))