fact: Definition ooextendable_O_prod_unit (A B C : Type) `{In O C} : ooExtendableAlong (O_prod_unit A B) (fun _ => C).
imports: HoTT.Basics HoTT.Types Equiv.BiInv Extensions HProp HFiber NullHomotopy Limits.Pullback PathAny Colimits.Pushout