fact: Definition Maybe_choose {a} (x y : Maybe a) : Maybe a := match x with | Nothing => y | Just _ => x end.
imports: Category.Lib Category.Theory.Coq.Functor Category.Theory.Coq.Applicative Category.Theory.Coq.Monad Category.Theory.Coq.Semigroup Category.Theory.Coq.Monoid Category.Theory.Coq.Traversable