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Corollary 7.3.5.3. Let $\operatorname{\mathcal{C}}$ be a category, let $\mathscr {G}: \operatorname{\mathcal{C}}\rightarrow \operatorname{Set_{\Delta }}$ be a diagram of simplicial sets, let $\operatorname{\mathcal{D}}$ be an $\infty $-category, and let $F_0: \underset { \longrightarrow }{\mathrm{holim}}( \mathscr {G} ) \rightarrow \operatorname{\mathcal{D}}$ be a diagram. The following conditions are equivalent:

$(1)$

The diagram $F_0$ admits a left Kan extension along the projection map $U: \underset { \longrightarrow }{\mathrm{holim}}( \mathscr {G} ) \rightarrow \operatorname{N}_{\bullet }(\operatorname{\mathcal{C}})$.

$(2)$

For every object $C \in \operatorname{\mathcal{C}}$, the diagram

\[ \mathscr {G}(C) \simeq \{ C\} \times _{ \operatorname{N}_{\bullet }(\operatorname{\mathcal{C}}) } \underset { \longrightarrow }{\mathrm{holim}}( \mathscr {G} ) \hookrightarrow \underset { \longrightarrow }{\mathrm{holim}}( \mathscr {G} ) \xrightarrow {F_0} \operatorname{\mathcal{D}} \]

admits a colimit in the $\infty $-category $\operatorname{\mathcal{D}}$.

Proof. For each object $C \in \operatorname{\mathcal{C}}$, the inclusion map

\[ \mathscr {G}(C) \hookrightarrow \operatorname{N}_{\bullet }( \operatorname{\mathcal{C}}_{/C} ) \times _{ \operatorname{N}_{\bullet }(\operatorname{\mathcal{C}}) } \underset { \longrightarrow }{\mathrm{holim}}(\mathscr {G} ) \simeq \underset { \longrightarrow }{\mathrm{holim}}( \mathscr {G}|_{ \operatorname{\mathcal{C}}_{/C} } ) \]

is right anodyne (Example 7.2.3.11), and therefore right cofinal. The desired result now follows by combining Proposition 7.3.5.1 with Corollary 7.2.2.10. $\square$