Definition 12.12.2. Let $\mathcal{A}, \mathcal{B}$ be abelian categories. Let $(F^ n, \delta _ F)$ and $(G^ n, \delta _ G)$ be $\delta $-functors from $\mathcal{A}$ to $\mathcal{B}$. A *morphism of $\delta $-functors from $F$ to $G$* is a collection of transformation of functors $t^ n : F^ n \to G^ n$, $n \geq 0$ such that for every short exact sequence $0 \to A \to B \to C \to 0$ of $\mathcal{A}$ the diagrams

are commutative.

## Comments (0)