proposition: Lemma is_nat_trans_yon_binprod : is_nat_trans _ _ yon_binprod_nat_trans_data.
proof: Proof. intros Z W f. use funextfun; intro g. now apply dirprodeq; use assoc'. Qed.
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Limits.BinProducts UniMath.CategoryTheory.Presheaf UniMath.CategoryTheory.opp_precat UniMath.CategoryTheory.Categories.HSET.Core UniMath.CategoryTheory.yoneda