# booktabs's horizontal rules aren't displayed with cifa document class

There seems to be a problem between the CIFA document class and the booktabs package. When I compile the following code, the horizontal lines are not displayed:

\documentclass{cifa}
\usepackage{booktabs}

\begin{document}
\begin{table}
\centering
\begin{tabular}{cc}
\toprule
$Cell_{11}$ & $Cell_{12}$ \\
\midrule
$Cell_{21}$ & $Cell_{22}$ \\
\bottomrule
\end{tabular}
\end{table}
\end{document}

If I use the article document class, the example compiles correctly. Any workaround?

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