Yigal Duppen
Copyright © 2002 Yigal Duppen.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts.
A copy of the license is included in Appendix B.