Exercise 1.1 · 习题

Exercise 1.1: Below is a sequence of expressions.
What is the result printed by the interpreter in response to each expression?
Assume that the sequence is to be evaluated in the order in which it is
presented.

10

(+ 5 3 4)

(- 9 1)

(/ 6 2)

(+ (* 2 4) (- 4 6))

(define a 3)

(define b (+ a 1))

(+ a b (* a b))

(= a b)

(if (and (> b a) ( b (* a b)))

b

a)

(cond ((= a 4) 6)

((= b 4) (+ 6 7 a))

(else 25))

(+ 2 (if (> b a) b a))

(* (cond ((> a b) a)

(( a b) b)

(else -1))

(+ a 1))

练习 1.1：下面是一组表达式。解释器对每个表达式求值后打印的结果是什么？假定这些表达式按给出的顺序依次求值。

10
(+ 5 3 4)
(- 9 1)
(/ 6 2)
(+ (* 2 4) (- 4 6))
(define a 3)
(define b (+ a 1))
(+ a b (* a b))
(= a b)
(if (and (> b a) ( b (* a b)))
b
a)
(cond ((= a 4) 6)
((= b 4) (+ 6 7 a))
(else 25))
(+ 2 (if (> b a) b a))
(* (cond ((> a b) a)
(( a b) b)
(else -1))
(+ a 1))