def METHOD_NAME(self) -> Tuple[bool, bool]:
    """Returns sign (is positive, is negative) of the expression.
    """
    # Same as argument.
    x_pos = self.args[0].is_nonneg()
    x_neg = self.args[0].is_nonpos()
    w_pos = self.args[1].is_nonneg()
    w_neg = self.args[1].is_nonpos()
    is_positive = (x_pos and w_pos) or (x_neg and w_neg)
    is_negative = (x_neg and w_pos) or (x_pos and w_neg)
    return is_positive, is_negative