proposition: Lemma algidr A : {in A, right_id (algid A) *%R}.
proof: Proof. rewrite /algid; case: algid_subproof => e _ /=; have /andP[-> _] := valP A. move/subvP=> idAe u /idAe/memv_capP[_]. by rewrite memv_ker !lfun_simp /= subr_eq0 => /eqP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype div tuple finfun bigop ssralg) mathcomp(finalg zmodp matrix vector poly)