練習 2.53

#lang racket

;: 練習 2.53

(list 'a 'b 'c) ;: '(a b c)

(list (list 'george)) ;: '((george))

(cdr '((x1 x2) (y1 y2))) ;: '((y1 y2))

(cadr '((x1 x2) (y1 y2))) ;: '(y1 y2)

(pair? (car '(a short list))) ;: #f

(memq 'red '((red shoes) (blue socks))) ;: #f

(memq 'red '(red shoes blue socks)) ;: (red shoes blue socks)