Proposition 10.2.2.14. The diagram of $\infty $-categories
\[ \xymatrix@R =50pt@C=50pt{ \operatorname{N}_{\bullet }( \operatorname{{\bf \Delta }}_{\operatorname{inj}} ) \ar [r] \ar [d] & \operatorname{N}_{\bullet }( \operatorname{{\bf \Delta }}) \ar [d] \\ \operatorname{N}_{\bullet }( \operatorname{{\bf \Delta }}_{\operatorname{inj}, +} ) \ar [r] & \operatorname{N}_{\bullet }( \operatorname{{\bf \Delta }}_{+} ) } \]
is a categorical pushout square.