proposition: Theorem size_unsize n : size (unsize n) = n.
proof: Proof. now induction n; simpl; auto. Qed.
imports: Category.Lib Category.Theory.Category Category.Theory.Isomorphism Category.Theory.Functor Category.Theory.Adjunction Category.Structure.Terminal Category.Structure.Cartesian Category.Structure.BiCCC Category.Instance.Fun Category.Instance.Coq Category.Instance.Sets Coq.Vectors.Vector