A \(\ref{Prop|\emph{prop|referenced}}\) functor \(\mathcal{C} \xrightarrow F \mathcal{D}\) A functor for which
\(\forall n \in \mathbb{N}: F(n)=n\)
For all \(m_1 \xrightarrow f m_2\) and \(n_1 \xrightarrow g n_2 \in \mathcal{C}\): \(F(f))+F(g)=F(f+g) \in \mathcal{D}\)