fact: Definition extension_isequiv_precompose {A : Type} {B : Type} (f : A -> B) (C : B -> Type) : IsEquiv (fun (g : forall b, C b) => g oD f) -> forall g, ExtensionAlong f C g.
imports: HoTT.Basics HoTT.Types Equiv.PathSplit PathAny Cubical.DPath Cubical.DPathSquare Colimits.Coeq Colimits.MappingCylinder