Example 10.2.6.17. For $n < 0$, the category $\operatorname{{\bf \Delta }}_{\mathrm{min}}^{\leq n}$ is empty. For $n = 0$, it contains a single object $[0]$, and no morphisms other than the identity morphism.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$