Fig. \[fig:SigmaCUT400-Dt\](b) does those for Set D and Set E. In the both figures, the result in the SM case \[Set A\] is also plotted. The cross sections for $\sqrt{s}=3$ TeV in Figs. \[fig:SigmaCUT400-Dt\](a) and (b) are greater than that for $\sqrt{s}=1$ TeV in Figs. \[fig:SigmaCUT400-t1\](a) and (b) due to logarithmic collinear enhancement at the $W$ bosons in the fusion process. The deviation rates from the SM prediction for Set B and Set C (the effect of $C_{t1}$) in Fig. \[fig:SigmaCUT400-Dt\](a) can be huge and is similar to those in Fig. \[fig:SigmaCUT400-t1\](a), while those for Set D and Set E (the effect of $C_{Dt}$) in Fig. \[fig:SigmaCUT400-Dt\](b) are much smaller than those in Fig. \[fig:SigmaCUT400-t1\](b). These differences in the energy dependence between the effects of $C_{t1}$ and $C_{Dt}$ may be used to extract their contributions separately at a multi-TeV collider such as CLIC.

In Fig. \[fig:ewa-vs-calchep\], we show the consistency of the numerical evaluation of the cross section. We plot the points evaluated by the full matrix-element calculation of the cross section for $e^- e^+ \to t \bar t \nu \bar \nu$ in CalcHEP[@calchep] and LanHEP[@lanhep] for the cases of Set A, Set B and Set C. The solid curves 