做了個難的

(define bubble
   (lambda (predicate b slst)
     (if (null? slst)
         (list b)
         (if (predicate (car slst) b)
             (cons (car (bubble predicate (car slst) (cdr slst)))
                   (cons b (cdr (bubble predicate (car slst) (cdr slst)))))
             (cons (car (bubble predicate b (cdr slst)))
                   (cons (car slst) (cdr (bubble predicate b (cdr slst)))))))))
;Value: bubble
(define sort
   (lambda (predicate lon)
     (if (null? lon)
         '()
         (cons (car (bubble predicate (car lon) (cdr lon)))
               (sort predicate (cdr (bubble predicate (car lon) (cdr lon))))))))
;Value: sort
(sort < '(8 2 5 2 3))
;Value 27: (2 2 3 5 8)
(sort >'(8 2 5 2 3))
;Value 28: (8 5 3 2 2)