def evaluate_g4( l, mu, s4 ):
    """
    Evaluate the fourth constraint equation and also return the jacobians
    Evaluate the constraint equation for lambda and mu and
    also return the jacobians

    :param float l: The value of the modulus lambda
    :param float mu: The value of the modulus mu
    :param float s4: The value of the constraint
    """

    return 3 * l + 2 * mu - s4**2, { 'lambda':3., 'mu':2., 's4':-2 * s4 }