proposition: Lemma functor_on_comp {B C:category} (F:[B,C]) {b b' b'':B} (g:b'-->b'') (f:b-->b') : F ▭ (g ∘ f) = F ▭ g ∘ F ▭ f.
proof: Proof. exact (functor_comp F f g). Defined.
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