fact: Definition ap_poption@{} (f : poption@{i} (T -> U)) (x : poption@{i} T) : poption@{j} U := match f , x with | pSome f , pSome x => pSome (f x) | _ , _ => pNone end.
imports: ExtLib.Structures.Functor ExtLib.Structures.Applicative ExtLib.Tactics.Injection