Section 1.3.1 of SICP. Higher order procedures. Note that I don't particularly like their approach to summation (i.e., their use of "next"). I prefer:
(define (sum f a b) (if (> a b) 0 (+ (f a) (sum f (+ a 1) b))))
The effect of next is obtained (in my version) by being a bit smarter about writing f.
Exercise 1.29, 1.30, 1.31, 1.32, 1.33
We reviewed exercises due today -- no new material or exercises
Finish Ch 1 of SICP. Lambda, let, and procedures as returned values.
Exercise 1.34, 1.37, 1.38