proposition: Theorem right_comp {x y z w : C} (f : y ~> z) (g : x ~> y) : right (z:=w) (f ∘ g) ≈ right f ∘ right g.
proof: Proof. apply (@second_comp _ O). Qed.
imports: Category.Lib Category.Theory.Category Category.Theory.Isomorphism Category.Structure.Cartesian Category.Structure.Initial Category.Construction.Opposite