PlanetPhysics/Generator

Let us consider an abelian category $$\mathcal{C}$$. Then, an object $$G$$ of $$\mathcal{C}$$ is called a generator if $$Hom_{\mathcal{C}}(G,A)$$ is nonzero for every nonzero object $$A$$ of $$\mathcal{C}$$.