fact: Definition equiv_extendable_pathsplit `{Funext} (n : nat) {A B : Type} (C : B -> Type) (f : A -> B) : ExtendableAlong n f C <~> PathSplit n (fun (g : forall b, C b) => g oD f).
imports: HoTT.Basics HoTT.Types Equiv.PathSplit PathAny Cubical.DPath Cubical.DPathSquare Colimits.Coeq Colimits.MappingCylinder