本文共 509 字，大约阅读时间需要 1 分钟。

    练习2.53

(a b c)((george))((y1 y2))(y1 y2)#f#f(red shoes blue socks)

    练习2.54

(define (equal? a b)  (cond ((and (null? a) (null? b)) true)	      ((null? a) false)	      ((null? b) false)	      (else (and (eq? (car a) (car b)) (equal? (cdr a) (cdr b))))))

    练习2.55

;; 'a 即为 (quote a)1 ]=> (quote a);Value: a;; 因此 ''abracadabra 等价于 (quote (quote abracadabra))1 ]=> (quote (quote abracadabra));Value: (quote abracadabra)1 ]=> ''abracadabra;Value: (quote abracadabra)1 ]=> (car (quote (quote abracadabra)));Value: quote

转载地址：http://yovbi.baihongyu.com/