### COMP 150PGM - Spring 2011 - Homework 1

Now due in class on February 7 due to snow

- Exercise 2.5 on page 39
- Find the conditional version of the two-variable chain rule: P(A, B | C)
= ...

You can do this by adding a conditioning variable to the ordinary chain rule,
or looking at what happens after the first step of the chain rule.
- Find the conditional version of the three-variable chain rule: P(A, B, C
| D) = ...
- Prove the "weak union" property (Formula 2.9 on page 25). You
will probably find 2 and 3 above helpful.