Warning 3.3.3.14. Though the category $\operatorname{{\bf \Delta }}_{X}^{\mathrm{nd}}$ is defined for any simplicial set $X$, it is primarily useful in the case where $X$ is braced (where we can use the description supplied by Example 3.3.3.12).
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$