Solution to SICP Exercise 1.1

Structure and Interpretation of Computer Programs

This morning I began my third attempt at reading the programming classic Structure and Interpretation of Computer Programs, otherwise known as SICP. My earlier attempts stalled for various reasons, but this time I hope to get through the entire book. As an incentive to finish, I’m publicly promising to post my solutions to all the exercises in the book on this blog, starting with Exercise 1.1:
>10
10

>(+ 5 3 4)
12

>(- 9 1)
8

>(/ 6 2)
3

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

>(define a 3)

>(define b (+ a 1))

>(+ a b (* a b))
19

>(= a b)
#f

>(if (and (> b a) ((cond ((= a 4) 6)
((= b 4) (+ 6 7 a))
(else 25))
16

>(+ 2 (if (> b a) b a))
6

>(* (cond ((> a b) a)
((< a b) b)
(else -1))
(+ a 1))
16