Homework 3

1. [20 points] Do Exercise 2.4 parts b, c, e, and f.

2. [20 points] Do Exercise 2.6 part b only.

3. [20 points] Do Exercise 2.9.

4. [20 points] Do Exercise 2.14.

5. [20 points]

1. Draw a state diagram of a pushdown automaton M that recognizes the language A of Exercise 2.9.
2. Give an informal description of the pushdown automaton M in part a. (Write up your answer in the same style as the textbook solution to Exercise 2.7.)

Extra credit: Prove that the complement of the language { ww : w ∈ {a,b}^* } is context-free by giving a CFG for it.