proposition: Lemma is_functor_lwhisker (f : C⟦a, b⟧) : is_functor (lwhisker_functor_data f).
proof: Proof. split; red; cbn. - intro g. apply lwhisker_id2. - intros g1 g2 g3 x y. apply pathsinv0, lwhisker_vcomp. Qed.
imports: UniMath.Tactics.EnsureStructuredProofs UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.PrecategoryBinProduct