proposition: Lemma split_sternD_left u v n : take ((2^n).+1) (sternD u v n.+1) = sternD u (u + v) n.
proof: Proof. by rewrite split_sternD; rewrite take_size_cat // size_sternD. 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)