Example 7.6.3.12. Let $f_0: X_0 \rightarrow X$ and $f_1: X_1 \rightarrow X$ be morphisms of Kan complexes. Applying the construction of Corollary 7.6.3.9, we obtain a pullback square
\[ \xymatrix@R =50pt@C=50pt{ X_0 \times ^{\mathrm{h}}_{X} X_1 \ar [r] \ar [d] & X_0 \ar [d]^-{f_0} \\ X_1 \ar [r]^-{f_1} & X } \]
in the $\infty $-category $\operatorname{\mathcal{S}}$.