$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
9.6
\begin{equation} \begin{gathered}\label{equation:essentially-finite-infinity-characterization} \xymatrix@R =50pt@C=50pt{ \operatorname{\partial \Delta }^{d} \ar [r] \ar [d] & K_0 \ar [d] \\ \Delta ^{d} \ar [r] & K, } \end{gathered} \end{equation}