Hom Functor

• ${\text{Hom}}_{\mathcal{C}}(A,-):\mathcal{C}\to \mathbf{Set}$
• ${\text{Hom}}_{\mathcal{C}}(-,B):{\mathcal{C}}^{op}\to \mathbf{Set}$

Covariant/contravariant Hom functors.