Hoe Work 3 (Due 2/1/05, points 10)

Change Text Book's exercise 2.2.4 b, and c to "ending with" rather than 
existing substring anywhere. [4]

Exc 2.2.5a (you may find eactly 2 0's easier to work with than at least 2 0's).
I will accept either answer. [3]

Exc 2.2.11, including the proof. [3]