(i) If $\Omega$ is a terminal object in a category $\mathcal{C}$, prove, for any $G \in \operatorname{obj}(\mathcal{C})$, that the projections $\lambda: G \sqcap \Omega \rightarrow G$ and $\rho: \Omega \sqcap G \rightarrow G$ are isomorphisms.
(ii) If $A$ is an initial object in a category $\mathcal{C}$, prove, for any $G \in$ obj $(\mathcal{C})$, that the injections $\lambda: G \rightarrow G \sqcup \Omega$ and $\rho: G \rightarrow$ $\Omega \sqcup G$ are isomorphisms.