\begin{table}[h]
\begin{tabular}{|l|llll}
\cline{1-1}
S         &                        &                                &                        &                        \\ \cline{1-2}
C         & \multicolumn{1}{l|}{A} &                                &                        &                        \\ \cline{1-3}
S         & \multicolumn{1}{l|}{S} & \multicolumn{1}{l|}{S}         &                        &                        \\ \cline{1-4}
\emptyset & \multicolumn{1}{l|}{B} & \multicolumn{1}{l|}{\emptyset} & \multicolumn{1}{l|}{b} &                        \\ \hline
C         & \multicolumn{1}{l|}{A} & \multicolumn{1}{l|}{C}         & \multicolumn{1}{l|}{A} & \multicolumn{1}{l|}{C} \\ \hline
c         & \multicolumn{1}{l|}{a} & \multicolumn{1}{l|}{c}         & \multicolumn{1}{l|}{a} & \multicolumn{1}{l|}{c} \\ \hline
\end{tabular}
\end{table}