proposition: Lemma exr_swap {x y z w} : @exr x y z w ∘ swap ≈ exl.
proof: Proof. solveit. Qed.
imports: Category.Lib Category.Theory.Category Category.Theory.Isomorphism Category.Theory.Functor Category.Functor.Product.Internal Category.Functor.Hom.Internal Category.Structure.Terminal Category.Structure.Cartesian Category.Structure.Cartesian.Closed Category.Structure.Monoidal.Closed Category.Instance.Sets