CatGloss

Let A\mathscr{A} be a category, II a set, and $(X_i){i \in I}afamilyofobjectsof a family of objects of \mathscr{A}$. A product of $(X_i){i \in I}consistsofanobject consists of an object P$ and a family of maps \(\Bigl(P \stackrel{p_i}{\longrightarrow} X_i\Bigr)_{i \in I}\) with the property that for all objects $A$ and families of maps \(\Bigl(A \stackrel{f_i}{\longrightarrow} X_i\Bigr)_{i \in I}\) there exists a unique map $\bar{f}{\colon}\linebreak[0] A \to Psuchthat such that p_i \circ \bar{f} = f_iforall for all i \in I$.