Using superscipt in argument of \dpd of commath package

Question

I am using the commath package to typeset derivatives and need to use a superscript in the argument supplied to \dpd. What I require is something like

\begin{equation}
    \dpd{}{X^{(j)}_0} f(X^{(j)}_0)
\end{equation}

but this does not compile. There is no problem with subscripts as

\begin{equation}
    \dpd{}{X_0} f(X^{(j)}_0)
\end{equation}

does compile. Does anyone know of a workaround?

(Note sure about the tag used - perhaps someone can suggest something more appropriate?)

Answer 1

Please observe additional parentheses in the solution:

\documentclass{article}
\usepackage{commath}

\begin{document}

\begin{equation}
    \dpd{}{{X^{(j)}_0}} f(X^{(j)}_0)
\end{equation}


\end{document}

Nevertheless, this package seems to be abandoned. As we cannot expect correcting its bugs, I wouldn't recommend using its macros.