proposition: Lemma triangle_l_inv {X Y Z : C} (g : C⟦Y,Z⟧) (f : C⟦X,Y⟧) : lassociator f (id₁ Y) g o linvunitor g ⋆⋆ id₂ f = id₂ g ⋆⋆ rinvunitor f.
proof: Proof. use inv_cell_eq. - is_iso. - is_iso. - cbn. apply triangle_l. 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