proposition: Lemma idtoiso_2_1_lwhisker {C : bicat} {X Y Z : C} (g : C⟦X,Y⟧) {f₁ f₂ : C⟦Y,Z⟧} (q : f₁ = f₂) : (idtoiso_2_1 _ _ q) ▻ g = idtoiso_2_1 _ _ (maponpaths (λ z, g · z) q).
proof: Proof. induction q ; cbn. apply lwhisker_id2. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.Bicategories.Core.Bicat UniMath.Bicategories.Core.Unitors UniMath.Bicategories.Core.Invertible_2cells UniMath.Bicategories.Morphisms.Adjunctions UniMath.Bicategories.Core.Univalence