fact: Hypothesis P_comma : forall (S : Functor C D) (T : Functor 1 D), P (S / T).
imports: Category.Core Functor.Core Category.Prod Functor.Prod.Core Category.Dual Functor.Dual Functor.Composition.Core InitialTerminalCategory.Core InitialTerminalCategory.Functors NatCategory FunctorCategory.Core Cat.Core Functor.Paths Comma.InducedFunctors Comma.Projection Types.Forall PathGroupoids HoTT.Tactics