方案:康德"不平等"

Question

我想在计划中这样做:

if ((car l) != (car (cdr (order l))) do something

特别是我写了这个:

((eq? (car l) (car (cdr (order l))) ) 
 (cons (count (car (order l)) (order l)) 
       (count_inorder_occurrences (cdr (order l))))) 

但它(car l)与(car (cdr (order l))平等相比.我想反而只是做错事eq?.我怎么能在我的例子中这样做？

谢谢

Answer 1

你可以用not它.

(cond
 ((not (eq? (car l) (cadr (order l))))
  (cons (count (car (order l)) (order l))
        (count-inorder-occurrences (cdr (order l))))
 ...)