def __phi(x):

    def __phi_f(s):
        t = (s / 7.5)
        return (tf.exp(((- s) / 2)) * ((((((1 + (3.5156229 * (t ** 2))) + (3.0899424 * (t ** 4))) + (1.2067492 * (t ** 6))) + (0.2659732 * (t ** 8))) + (0.0360768 * (t ** 10))) + (0.0045813 * (t ** 12))))

    def __phi_g(s):
        t = (s / 7.5)
        return (tf.sqrt((2 / s)) * ((((((((0.39894228 + (0.01328592 * (t ** (- 1)))) + (0.00225319 * (t ** (- 2)))) - (0.00157565 * (t ** (- 3)))) + (0.0091628 * (t ** (- 4)))) - (0.02057706 * (t ** (- 5)))) + (0.02635537 * (t ** (- 6)))) - (0.01647633 * (t ** (- 7)))) + (0.00392377 * (t ** (- 8)))))
    a = 7.5
    return ((__phi_f(tf.minimum(x, a)) - __phi_f(a)) + __phi_g(tf.maximum(x, a)))
def __phi(x):

    def __phi_f(s):
        t = (s / 7.5)
        return (tf.exp(((- s) / 2)) * ((((((1 + (3.5156229 * (t ** 2))) + (3.0899424 * (t ** 4))) + (1.2067492 * (t ** 6))) + (0.2659732 * (t ** 8))) + (0.0360768 * (t ** 10))) + (0.0045813 * (t ** 12))))

    def __phi_g(s):
        t = (s / 7.5)
        return (tf.sqrt((2 / s)) * ((((((((0.39894228 + (0.01328592 * (t ** (- 1)))) + (0.00225319 * (t ** (- 2)))) - (0.00157565 * (t ** (- 3)))) + (0.0091628 * (t ** (- 4)))) - (0.02057706 * (t ** (- 5)))) + (0.02635537 * (t ** (- 6)))) - (0.01647633 * (t ** (- 7)))) + (0.00392377 * (t ** (- 8)))))
    a = 7.5
    return ((__phi_f(tf.minimum(x, a)) - __phi_f(a)) + __phi_g(tf.maximum(x, a)))