When reading a CS paper, I encountered an arrow like $\langle f_1, \ldots, f_n \rangle : \langle A_1, \ldots, A_n \rangle \rightarrow \langle B_1, \ldots, B_n \rangle$. The author took it for granted to mean a collection of arrows $f_1 : A_1 \rightarrow B_1$, ..., $f_n : A_n \rightarrow B_n$. I wonder if there is such a notion in category theory. If it is, I would appreciate a reference. Thanks.
Based on the information provided, the arrow $\langle f_1,\dots,f_n\rangle$ can be regarded as an arrow in the product category $\mathscr D=\mathscr C\times\mathscr C\times\dots\times\mathscr C$ if each arrow $f_i$ originates in $\mathscr C$.