Kerodon

$\Newextarrow{\xRightarrow}{5,5}{0x21D2}$ $\newcommand\empty{}$
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
7.61
\begin{equation} \begin{gathered}\label{equation:all-squares-in-QCat2} \xymatrix@R =50pt@C=50pt{ \operatorname{\mathcal{C}}'_{01} \ar [r] \ar [d] & \operatorname{\mathcal{C}}'_{0} \ar [d]^-{F'_{0}} \\ \operatorname{\mathcal{C}}_{1} \ar [r]^-{F_1} & \operatorname{\mathcal{C}}} \end{gathered} \end{equation}