proposition: Lemma oner_neq0 : oneU != 0.
proof: Proof. by rewrite -(inj_eq val_inj) SubK raddf0 oner_neq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)