!=: 1%g).Lemma abelem_rV_M : {in E &, {morph ErV : x y / (x * y)%g >-> x + y}}.
Proof. by case/misomP: (xchooseP ab_rV_P) => fM _; mo

(* Specifications: *)
Canonical abelem_rV_morphism := Morphis
Hint Resolve mem_im_abelem_rV su