proposition: Lemma id2_left_CAT {C D : category} {F G : [C, D]} (α : [C, D]⟦F, G⟧) : id2_CAT F · α = α.
proof: Proof. apply id_left. Qed.
imports: UniMath.Foundations.PartD UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.whiskering