show the results of cross sections for $e^-
e^+ \to W^-_L W^+_L\nu\bar\nu\to t \bar t \nu \bar \nu$ by using EWA for Set A, Set B and Set C. Both results agree for greater Higgs boson mass. The both results agree with each other in about 20-30 % error for $m_H^{} {\mbox{ \raisebox{-1.0ex}{$\stackrel{\textstyle >}
{\textstyle \sim}$ }}}400$ GeV where the longitudinal component of the $W$ bosons is dominant. It is also found that even for relatively lower $m_H^{}$ values (${\mbox{ \raisebox{-1.0ex}{$\stackrel{\textstyle <}
{\textstyle \sim}$ }}}400$ GeV) the deviation from the SM prediction (Set A) evaluated by using CalcHEP/LanHEP are huge (more than 100 %) for both Set B and Set C. Therefore our conclusion originally obtained from the analysis in the EWA can also be applied to the small $m_H^{}$ region where the EWA cannot be used for a valid calculation. For a light Higgs boson with its mass to be less than about 150 GeV, the Higgs-top interaction is expected to be studied via the process $e^-e^+ \to t \bar t H$[@han].

The SM value of the cross section for $e^-e^+ \to W^-W^+ \nu \bar \nu
 \to t \bar t \nu \bar \nu$ is order 1fb for heavy Higgs 