ICS H21 • UC IRVINE • DAVID G. KAY • FALL 2009

**Third Homework**

This assignment is due at the start of lab on Monday, October 12. There are fewer questions on this homework than on last week's, but the concepts (of working with lists) are fundamental to the rest of the cours.

**(1) ** If there were problems from
Chapter 6 that you didn't get through when you worked on the previous
homework assignment, be sure that you go through them now so that you
know how to do them. Likewise, make sure you can do all the Scheme Finger Exercises; you should have these concepts down as you start to work with lists.

**(2)** As you read Chapter 9 of the HtDP
text, do exercises 9.1.1, 9.1.2, 9.2.3, and 9.5.2 (except write how-many-strings instead of
how-many-symbols).

**(3)** As you read Chapter 10, do exercise 10.1.1.
As you look at exercises 10.1.2, 10.1.4, 10.1.5,
and 10.1.6 (which are assigned for the lab below), note that they perform
these related tasks: Change every item (in 10.1.4), keep selected items
(in 10.1.5), substitute new values (in 10.1.6). You'll see these patterns
over and over. Determine which of those patterns exercise 10.1.7 follows
most closely.

Do exercises 10.2.1, 10.2.3, 10.2.4, 10.2.5, 10.2.6, and 10.2.8, all of which are similar to the restaurant examples we did in class.

**(4)** In Chapter 11, the authors use
the concepts we already know to define the natural numbers. Even if you
don't find number theory particularly compelling, you might appreciate
how elegantly it all fits together.

Based in part on ICS H21assignments by David G. Kay from Fall 2001; modified by David G. Kay, Fall 2004–Fall 2009.

David G. Kay, kay@uci.edu

Wednesday, October 7, 2009 8:29 PM