\[sec:tm\]. In the left panel of Fig. \[fig:Ref\], we compare the calculated results for $N=1500$ with the experiments on highly oriented pyrolithic graphite (HOPG). [@Taft1965; @Djurisic1999] We can get some conclusions, first, it is difficult to consider that HOPG is dominated by AB stacking, because the peak structure does not appear at $2 \gamma_1$ in the measured reflectivity. [@Djurisic1999] On the other hand, the corresponding peak was observed for natural graphite, [@Taft1965; @Hanfland1989a] and the value of $\gamma_1$ is estimated to be a reasonable value 0.4 eV. We therefore believe that AB stacking is dominated indeed in natural graphite. However, the following points need further clarifications on the low-energy structure of the conductivity. As shown in Fig. 2, the layered conductivity decreases monotonically below the peak, while the bunched conductivity recovers $\pi \alpha$ at the zero energy limit. The conductivity deduced for natural graphite by Taft and Pilip (Fig. 6 in Ref. ) is consistent with this behavior of the layered conductivity. However, this consistency should not be used to immediately determine the validity of the description of the layered conductivity, because AA stacking may be present in natural graphite. As shown in Appendix \[app:aa\], AA stacking increases layered conductivity 