(*
 * Copyright (c) 1991 Joe Christy
 *                    Mathematical Sciences Research Institute 
 *                    1000 Centennial Drive
 *                    Berkeley, CA 94720
 *
 * email address: joe@msri.org
 *
 * This software is copyrighted as noted above.  It may be freely copied,
 * modified, and redistributed, provided that the copyright notice is
 * preserved on all copies.
 *
 * There is no warranty or other guarantee of fitness for this software,
 * it is provided solely "as is".  Bug reports or fixes may be sent
 * to the authors, who may or may not act on them as they desire.
 *
 * You may not include this software in a program or other software product
 * without supplying the source, or without informing the end-user that the
 * source is available for no extra charge.
 *
 * If you modify this software, you should include a notice giving the
 * name of the person performing the modification, the date of modification,
 * and the reason for such modification.
 *)