def c2st_rfi(acc_prop,
             acc_base,
             M_prop,
             M_base,
             g):
    """
    Args:
        acc_prop (float): Proposed model accuracy.
        acc_base (float): Baseline model accuracy.
        M_prop   (int): Number of parameters for proposed model.
        M_base   (int): Number of parameters for baseline model.
        g        (function): Scalar-valued function.
    """
    delta_prop = g(acc_prop - 0.5)
    delta_base = g(acc_base - 0.5)
    
    return 1 - (M_prop / M_base) * (delta_prop / delta_base)