2.53 Exercise 2.53
> (list 'a 'b 'c) (mcons 'a (mcons 'b (mcons 'c)))
> (list (list 'george)) (mcons (mcons 'george))
> (cdr '((x1 x2) (y1 y2))) (mcons (mcons 'y1 (mcons 'y2)))
> (cadr '((x1 x2) (y1 y2))) (mcons 'y1 (mcons 'y2))
> (pair? (car '(a short list))) #f
> (memq 'red '((red shoes) (blue socks))) #f
> (memq 'red '(red shoes blue socks)) (mcons 'red (mcons 'shoes (mcons 'blue (mcons 'socks))))