fact: Definition nattrans_arrow_composition {C:category} {X X':[C^op,HSET]} {c:C} : c⇒X -> X-->X' -> c⇒X' := λ x q, (q:_ ⟹ _) c (x:(X:_⟶_) c:hSet).
imports: UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.opp_precat UniMath.CategoryTheory.yoneda UniMath.CategoryTheory.Categories.HSET.Core UniMath.CategoryTheory.Categories.HSET.MonoEpiIso UniMath.Foundations.Preamble UniMath.Foundations.Sets UniMath.MoreFoundations.Tactics