proposition: Lemma L7 n c p : c <> zero -> FS n * cons c p zero = cons c p zero.
proof: Proof. intro H; rewrite (L6 n _ _ H). now rewrite mult_a_0. 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)