/*
 * @(#)$Id: gcd2,v 1.2 1997/10/09 17:14:49 img Exp $
 *
 * $Log: gcd2,v $
 * Revision 1.2  1997/10/09 17:14:49  img
 * updates
 *
 * Revision 1.1  1994/09/16 09:38:16  dream
 * Initial revision
 *
 */

problem([]==>x:pnat=>y:pnat=>less(x,y)=>gcd(x,y)=gcd(x,minus(y,x))in pnat,_,_,_).
