Permission to use, copy, modify, and distribute this software and
its documentation with or without modi?cations and for any purpose
and without fee is hereby granted, provided that any copyright
notices appear in all copies and that both those copyright notices
and this permission notice appear in supporting documentation, and
that the names of the contrib- utors or copyright holders not be
used in advertising or publicity pertaining to distribution of the
software without speci?c prior permission.