proposition: Lemma sternD_sumC u v n : sternD_sum u v n = sternD_sum v u n.
proof: Proof. by rewrite !sternD_sumE addnC. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype order bigop ssralg) mathcomp(div ssrnum ssrint rat prime path binomial) mathcomp(tuple finset) gaia(fibm)