Exercise 9.1.2.15. Let $\operatorname{\mathcal{C}}$ be an $\infty $-category and let $n \geq 1$ be an integer. Show that the homotopy category $\mathrm{h} \mathit{\operatorname{\mathcal{C}}}$ satisfies condition $(\ast _ n)$ of Definition 9.1.2.1 if and only if $\operatorname{\mathcal{C}}$ satisfies condition $(\ast '_{n})$ of Lemma 9.1.2.12.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$