proposition: Lemma left_unit_inv_assoc₂ {X Y Z : C} (g : C⟦Y,Z⟧) (f : C⟦X,Y⟧) : rinvunitor (g ∘ f) = lassociator f g (id₁ Z) o (rinvunitor g ▻ f).
proof: Proof. rewrite left_unit_inv_assoc. rewrite <- !vassocr. rewrite rassociator_lassociator. rewrite id2_right. apply idpath. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.Bicategories.Core.Bicat UniMath.Bicategories.Core.Invertible_2cells UniMath.Bicategories.Core.Unitors