proposition: Lemma plus_compat: forall n p, FS n + FS p = FS (S n + p).
proof: Proof. reflexivity. Qed.
imports: Coq(Arith Max Bool Lia Compare_dec Relations Ensembles Wellfounded Bool RelationClasses Operators_Properties ArithRing Logic.Eqdep_dec) hydras(More_Arith Restriction DecPreOrder) hydras(OrdNotations)