Commutative diagram axiom

Axiom D (Commutative diagram axiom). The following commutative squares are pushouts of \(\infty \)-categories:

Here the first square is required to be a pushout for every \(n \geq 1\). In the last square, the right and bottom maps are the inclusions, while the top and left maps send the vertex \(\{l+1\}\) to the corresponding vertex with the same label.