Mateusz Bagiński comments on Multiplicative Operations on Cartesian Frames

[Mateusz Bagiński]

there exists a unique morphism $\varphi :C_0\otimes C_1\to D^{\ast }$such that ${\varphi }_i=\varphi \circ {\iota }_i$.

should be $\varphi :C_0\oplus C_1\to D^{\ast }$