proposition: Lemma variation0r b : variation 0 b = 0.
proof: Proof. by rewrite /variation mul0r ltxx mulr0. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice path fintype) mathcomp(div bigop order ssralg poly polydiv ssrnum perm zmodp ssrint) mathcomp(polyorder polyrcf interval matrix mxtens)