/*
 * @(#)$Id: pi1,v 1.1 1994/09/16 09:37:56 dream Exp $
 *
 * $Log: pi1,v $
 * Revision 1.1  1994/09/16 09:37:56  dream
 * Initial revision
 *
 */

pi1(x)<==>spread(x,[a,~,a]).
