proposition: Lemma yon_binprod_is_iso : @is_iso [C^op, HSET, has_homsets_HSET] _ _ yon_binprod_nat_trans.
proof: Proof. use is_iso_from_is_z_iso. exists yon_binprod_inv_nat_trans. split; apply (nat_trans_eq has_homsets_HSET); intro Z; use funextfun; intro f. - cbn; unfold yon_binprod_nat_trans_data, yon_binprod_inv_nat_trans_data. now rewrite <- (BinProductArrowEta _ _ _ _ _ _). - use dirprodeq; cbn; unfold yon_binprod_inv_nat_trans_data; [use BinProductPr1Commutes | use BinProductPr2Commutes]. 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