**Week 7** due 24/2.

Chapter 22 exercises 4a, 22, 23.

chapter 23
exercise 1i,vi,vii,viii,x,xi,xiv,xv,xviii,xx (hint: for the last, you'll need problem
18.17) (checksum: there are ten parts to do in total).

chapter 23 exercises 4, 7a, 9a (just the first statement), 12, 26.

Optional: chapter 22 problems 3, 11, 22.