Proposition proj2_tensor {x' x y : C} (f : x' --> x) : (f #⊗ identity y) · proj2 = proj2. Proof. unfold proj2. rewrite !assoc. apply maponpaths_2. rewrite <- tensor_comp_id_r. rewrite del_natural. reflexivity. Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Prelude. Require Import UniMath.CategoryTheory.Limits.Terminal. Require Import UniMath.CategoryTheory.Monoidal.Categories. Require Import UniMath.CategoryTheory.Monoidal.Structure.Cartesian. Require Import UniMath.CategoryTheory.Monoidal.Structure.Symmetric. Require Import UniMath.CategoryTheory.Monoidal.Structure.SymmetricDiagonal. Import MonoidalNotations.