Exercise 8.4.1.4. Let $\operatorname{\mathcal{C}}$ denote the category of partially ordered sets, and let $\operatorname{{\bf \Delta }}_{\leq 1}$ denote the full subcategory of $\operatorname{\mathcal{C}}$ spanned by the objects $[0]$ and $[1]$. Show that $\operatorname{{\bf \Delta }}_{\leq 1}$ is a dense subcategory of $\operatorname{\mathcal{C}}$.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$