Remark 8.2.2.4. Let $\lambda = (\lambda _{-}, \lambda _{+}): \operatorname{\mathcal{C}}\rightarrow \operatorname{\mathcal{C}}_{-}^{\operatorname{op}} \times \operatorname{\mathcal{C}}_{+}$ and $\mu = (\mu _{-}, \mu _{+} ): \operatorname{\mathcal{D}}\rightarrow \operatorname{\mathcal{D}}_{-}^{\operatorname{op}} \times \operatorname{\mathcal{D}}_{+}$ be couplings of $\infty $-categories, and suppose we are given a morphism of couplings
It follows from Proposition 8.2.1.7 that the functor $F$ carries $\lambda _{-}$-cocartesian morphisms of $\operatorname{\mathcal{C}}$ to $\mu _{-}$-cocartesian morphisms of $\operatorname{\mathcal{D}}$, and $\lambda _{+}$-cocartesian morphisms of $\operatorname{\mathcal{C}}$ to $\mu _{+}$-cocartesian morphisms of $\operatorname{\mathcal{D}}$.