This book is free, but it is not in the public domain. It is published under the terms of the GNU Free Documentation License. This license allows redistribution and modification under certain terms. For example, you can:

Post an unmodified copy of this textbook on your own Web site.

Give away or sell printed, unmodified copies of this book, as long as they meet the requirements of the license.

Post on the web or otherwise distribute modified copies, provided that the modifications are clearly noted in accordance with the license.

Stephen Schaub

Department of Computer Science

Bob Jones University

Greenville, SC 29614, USA

Email: sschaub@bju.edu

September, 2005