// This software is copyright (c) 1996-2005 by
//      John Tromp
//      Insulindeweg 908
//      1095 DX Amsterdam
//      Netherlands
// E-mail: tromp@cwi.nl
//
// This notice must not be removed.
// This software must not be sold for profit.
// You may redistribute if your distributees have the
// same rights and restrictions.