Subscript:
\begin{equation}
\mathrm{c}\mathrm{-Critical\ value}\nonumber \\
\end{equation}\begin{equation}
\mathrm{l}\mathrm{-Saturated\ liquid\ phase}\nonumber \\
\end{equation}\begin{equation}
\mathrm{v}\mathrm{-Saturated\ gas\ phase}\nonumber \\
\end{equation}\begin{equation}
\mathrm{o}\mathrm{-Vapor\ pressure\ data\ point,\ e.g.\ }\mathrm{T}_{\mathrm{o}}\mathrm{,}\mathrm{P}_{\mathrm{o}}.\nonumber \\
\end{equation}\begin{equation}
\mathrm{r}\mathrm{-Reduced\ property,\ e.g.\ }\mathrm{T}_{\mathrm{r}}\mathrm{=}\frac{\mathrm{T}}{\mathrm{T}_{\mathrm{c}}\mathrm{,}\mathrm{P}_{\mathrm{r}}\mathrm{=}\frac{\mathrm{P}}{\mathrm{P}_{\mathrm{c}}}}.\nonumber \\
\end{equation}