Generator version of `pure_nash_brute`.

    Parameters
    ----------
    g : NormalFormGame
    tol : scalar(float), optional(default=None)
        Tolerance level used in determining best responses. If None,
        default to the value of the `tol` attribute of `g`.

    Yields
    ------
    out : tuple(int)
        Tuple of Nash equilibrium pure actions.

def pure_nash_brute_gen(g, tol=None):
    """
    Generator version of `pure_nash_brute`.

    Parameters
    ----------
    g : NormalFormGame
    tol : scalar(float), optional(default=None)
        Tolerance level used in determining best responses. If None,
        default to the value of the `tol` attribute of `g`.

    Yields
    ------
    out : tuple(int)
        Tuple of Nash equilibrium pure actions.

    """
    for a in np.ndindex(*g.nums_actions):
        if g.is_nash(a, tol=tol):
            yield a