docs: def Bern_to_Fierz_lep(C,ddll):
      """From semileptonic Bern basis to Fierz semileptonic basis for Class V.
      C should be the corresponding leptonic Fierz basis and
      `ddll` should be of the form 'sbl_enu_tau', 'dbl_munu_e' etc."""
      ind = ddll.replace('l_','').replace('nu_','')
      return {'F' + ind + '9': C['1' + ind] + 10 * C['3' + ind],
              'F' + ind + '10': -6 * C['3' + ind],
              'F' + ind + 'S': C['5' + ind] + 40 * C['9' + ind],
              'F' + ind + 'P': 24 * C['9' + ind],
              'F' + ind + 'T': C['7' + ind] / 2 + C['7p' + ind] / 2 - 8 * C['9' + ind] - 8 * C['9p' + ind],
              'F' + ind + 'T5': C['7' + ind] / 2 - C['7p' + ind] / 2 - 8 * C['9' + ind] + 8 * C['9p' + ind],
              'F' + ind + '9p': C['1p' + ind] + 10 * C['3p' + ind],
              'F' + ind + '10p': 6 * C['3p' + ind],
              'F' + ind + 'Sp': C['5p' + ind] + 40 * C['9p' + ind],
              'F' + ind + 'Pp': -24 * C['9p' + ind],
              }