(define pi 3.14159)
(define radius 10)
(* pi (* radius radius))
(define circumference (* 2 pi radius))
circumference
(define pi 100000)
pi
circumference
(define (square x) (* x x))
(define (sum-of-squares x y) (+ (square x) (square y)))原文：http://www.cnblogs.com/zhjch/p/4222724.html