Corollary 4.5.9.18. Let $U: \operatorname{\mathcal{C}}\rightarrow \operatorname{\mathcal{B}}$ be an exponentiable morphism of simplicial sets. For every $\infty $-category $\operatorname{\mathcal{D}}$, the projection map $\pi : \operatorname{Fun}( \operatorname{\mathcal{C}}/\operatorname{\mathcal{B}}, \operatorname{\mathcal{D}}) \rightarrow \operatorname{\mathcal{B}}$ is an isofibration of simplicial sets.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$