fact: Definition extendable_postcompose (n : nat) {A B : Type} (C D : B -> Type) (f : A -> B) (g : forall b, C b -> D b) `{forall b, IsEquiv (g b)} : ExtendableAlong n f C -> ExtendableAlong n f D := extendable_postcompose' n C D f (fun b => Build_Equiv _ _ (g b) _).
imports: HoTT.Basics HoTT.Types Equiv.PathSplit PathAny Cubical.DPath Cubical.DPathSquare Colimits.Coeq Colimits.MappingCylinder