fact: Definition functorial_morphism_of_object_of : (S / T) -> (S' / T') := fun x => CommaCategory.Build_object S' T' (AF (CommaCategory.a x)) (BF (CommaCategory.b x)) (TB (CommaCategory.b x) o CF _1 (CommaCategory.f x) o TA (CommaCategory.a x)).
imports: Functor.Core NaturalTransformation.Core Functor.Composition.Core NaturalTransformation.Composition.Core NaturalTransformation.Composition.Laws Functor.Paths Category.Strict HoTT.Tactics PathGroupoids Types.Forall