## CS4123 Theory of Computation. B97

### Prof. Carolina Ruiz

Department of Computer Science

Worcester Polytechnic Institute

# Homework 1

Due on Monday, Nov. 10 at 2:30 pm

Problems:

- From the textbook:
Exercises and Problems:
3.2, 3.3, 3.4, 3.7, 3.8, 3.11, 3.13, 3.14, 3.16

Additional Problems for students taking this course for graduate
credit:

- From the textbook:
Exercises and Problems: 3.9, 3.12.
- Prove that a language L is decidable iff L and its complement
CL are both semidecidable.
(Note: CL = Sigma* - L)