$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
1.4
\begin{eqnarray} \label{equation:relation-semisimplicial-identity} \widetilde{\delta }^{j}_{n} \circ \widetilde{\delta }_{n-1}^{i} & = & \widetilde{\delta }_{n}^{i} \circ \widetilde{\delta }_{n-1}^{j-1} \end{eqnarray}