proposition: Lemma included_FNth : included R' P -> forall n, included R' (Dom (Fnth n)).
proof: Proof. auto. Qed.
imports: CoRN.tactics.CornTac CoRN.algebra.CSums CoRN.algebra.CAbMonoids Coq.Sorting.Permutation CoRN.util.SetoidPermutation Coq.Setoids.Setoid Coq.Classes.Morphisms Coq(Lia)