Welcome to MzScheme version 360, Copyright (c) 2004-2006 PLT Scheme Inc.
> (if 2 3 4)
3
> (if 0 3 4)
3
> 
(1 . 2)
> (car (cons 1 2))
1
> (cdr (cons 1 2))
2
> (define a (cons 3 4))
> a
(3 . 4)
> (car a )
3
> (cdr a )
4
> (define b (cons 1 a))
> b
(1 3 . 4)
> (define a (cons 1 ()))
> a
(1)
> (cons 3 a)
(3 1)
>