# CMPSCI 250: Introduction to Computation

### David Mix Barrington

### Spring, 2012

# Homework Assignment #9

#### Posted Friday 20 April 2012

#### Due on paper to me or to CMPSCI main office by 4:00 p.m., Tuesday
1 May 2012.

There are eight questions for 60 total points plus 20 extra credit.
All are from
the textbook, *
Mathematical Foundation for Computer Science*. Note that the book has
both Exercises and Problems -- make sure you are doing a Problem and not the
Exercise with the same number. 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.

- Problem 14.7.5 (10) In (b), L is an arbitrary language and your answer
should be in terms of L.
- Problem 14.8.4 (10)
- Problem 14.10.6 (10)
- Problem 14.10.7 (10)
- Problem 15.1.4 (10XC) For part (b), you may describe the action of the
2WDFA in English if you make it clear that only O(n) states are needed.
- Problem 15.6.3 (10XC) "Build" here means to give a state table.
- Problem 15.6.4 (10) Here you can be less formal about how you are
changing the state table if you can describe clearly what the new TM does.
- Problem 15.8.5 (10) Here you can be pretty informal about the TM's.

Last modified 9 May 2012