public boolean findAtSW(int piece, int x, int y){
		if(x==7 || y==0 || b.get(x+1,y-1)==EMPTY_PIECE) return false;
		else if(b.get(x+1,y-1)==piece) return true;
		else return findAtSW(piece,x+1,y-1); // there is an opponent
	} // end findAtSW