# CMPSCI 401: Theory of Computation

### David Mix Barrington

### Spring, 2013

# Homework Assignment #2

#### Posted Friday 8 February 2013

#### Due on paper in class, Tuesday 19 February 2013

There are twelve questions for 100 total points plus 10 extra credit.
All but one are
the textbook, *Introduction to the Theory of Computation*
by Michael Sipser (second edition).
The number in parentheses following each problem
is its individual point value.

Students are responsible for understanding and following
the academic honesty
policies indicated on this page.

Note in green added 17 February.

- Problem 1.49 (10) The definitions of the
languages B and C could perhaps be stated more clearly. B is the
set of all w for which there exist and integer k ≥ 1 and a string
y such that w = 1
^{k}y and y has at least k 1's. C is the
set of all w for which there exist such a k and y such that y has at
most k 1's.
- Problem 1.54 (10)
- Problem 1.61 (10)
- Problem 1.62 (10)
- Exercise 2.4 parts b, c, e, f only (10)
- Exercise 2.5 parts b, c, e, f only (10)
- Exercise 2.6 part b only (5)
- Exercise 2.11 (5)
- Exercise 2.17 (10)
- Problem 2.19 (10)
- Problem 2.21 (10XC)
- Problem 2.44 (10)

Last modified 19 February 2013