Kerodon

$\Newextarrow{\xRightarrow}{5,5}{0x21D2}$ $\newcommand\empty{}$
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$

Exercise 4.5.2.13. Show that the diagram of $\infty $-categories

\[ \xymatrix@R =50pt@C=50pt{ \{ 0\} \ar [r] \ar [d] & \Delta ^1 \ar [d] \\ \Delta ^1 \ar [r] & \Delta ^1 } \]

is a homotopy pullback square which is not a categorical pullback square.