proposition: Lemma comp_ff_is_ff (C D E : precategory) (F : functor C D) (ffF : fully_faithful F) (G : functor D E) (ffG : fully_faithful G) : fully_faithful (functor_composite F G).
proof: Proof. unfold fully_faithful in *. intros ? ?; apply (pr2 (weqcomp (_,, ffF _ _) (_,, ffG _ _))). Qed.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Univalence UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.TransportMorphisms UniMath.CategoryTheory.Core.Univalence