code: def onesided_cl_to_dlnl(cl):
      
      alpha = 1.0 - cl
      return 0.5 * np.power(np.sqrt(2.) * special.erfinv(1 - 2 * alpha), 2.)
docs: Compute the delta-loglikehood values that corresponds to an
      upper limit of the given confidence level.
  
      Parameters
      ----------
      cl : float
          Confidence level.
  
      Returns
      -------
      dlnl : float
          Delta-loglikelihood value with respect to the maximum of the
          likelihood function.