fact: Definition ooextendable_functor_sum {A B A' B'} (f : A -> A') (g : B -> B') (P : A' + B' -> Type) (ef : ooExtendableAlong f (P o inl)) (eg : ooExtendableAlong g (P o inr)) : ooExtendableAlong (functor_sum f g) P.
imports: HoTT.Basics HoTT.Types Equiv.PathSplit PathAny Cubical.DPath Cubical.DPathSquare Colimits.Coeq Colimits.MappingCylinder