- $(1)$
The simplicial set $\operatorname{\mathcal{QC}}_{\operatorname{Obj}}$ is an $\infty $-category.
- $(2)$
The projection map $\widetilde{V}: \operatorname{ \pmb {\mathcal{QC}} }_{\operatorname{Obj}} = \operatorname{ \pmb {\mathcal{QC}} }_{\Delta ^{0} / } \rightarrow \operatorname{ \pmb {\mathcal{QC}} }$ restricts to a functor
\[ V: \operatorname{\mathcal{QC}}_{\operatorname{Obj}} = \operatorname{Pith}( \operatorname{ \pmb {\mathcal{QC}} }_{\operatorname{Obj}} ) \rightarrow \operatorname{Pith}(\operatorname{ \pmb {\mathcal{QC}} }) = \operatorname{\mathcal{QC}}. \]- $(3)$
The diagram
\[ \xymatrix@R =50pt@C=50pt{ \operatorname{\mathcal{QC}}_{\operatorname{Obj}} \ar [r] \ar [d]^-{V} & \operatorname{ \pmb {\mathcal{QC}} }_{\operatorname{Obj}} \ar [d]^-{ \widetilde{V} } \\ \operatorname{\mathcal{QC}}\ar [r] & \operatorname{ \pmb {\mathcal{QC}} }} \]is a pullback square of simplicial sets.
- $(4)$
The functor $V$ is a cocartesian fibration of $\infty $-categories.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
Proof. Assertion $(1)$ follows from Proposition 5.4.5.6. Since $\widetilde{V}$ is an interior fibration (Proposition 5.5.6.9), assertions $(2)$ and $(3)$ follow from Proposition 5.4.7.10. Assertion $(4)$ is a special case of Corollary 5.4.7.11. $\square$