Copyright: Copyright 2003-2014, Knowledge Science Group, University of Calgary.
Permission to use, copy, modify, distribute and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting documentation. The
Knowledge Science Group makes no representations about the suitability of
this software for any purpose. It is provided "as is" without express or
implied warranty.