fact: Definition Maybe_map `(f : X → Y) (x : Maybe X) : Maybe Y := match x with | Nothing => Nothing | Just x' => Just (f 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