@property
def is_switch(G):
    """
        A game is a switch if it's left and right options are numbers, and G_L > G_R.

        Returns
        -------
        number : bool
            Whether G is a switch or not.
        """
    if len(G._left) == len(G._right) == 1:
        G_L = next(iter(G._left))
        G_R = next(iter(G._right))
        if G_L.is_number and G_R.is_number and G_L > G_R:
            return True
    return False
