public boolean alone( int x, int y )
	{
		return (
				(!exists( x - 1, y ) || board[y][x - 1] == EMPTY) &&
				(!exists( x + 1, y ) || board[y][x + 1] == EMPTY) &&
				(!exists( x, y - 1 ) || board[y - 1][x] == EMPTY) && 
				(!exists( x, y + 1 ) || board[y + 1][x] == EMPTY)
		);
	}