proposition: Lemma intS (n : nat) : n.+1%:Z = 1 + n%:Z.
proof: Proof. by rewrite -PoszD. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)