fact: Definition right_triple {A B C} (x : A) (y : B) (z : C) : A * (B * C) := (x, (y, z)).
imports: Coq.Lists.List Category.Lib Category.Theory.Coq.Functor Category.Theory.Coq.Applicative Category.Theory.Coq.Monad Category.Theory.Coq.Semigroup Category.Theory.Coq.Monoid