proposition: Lemma fmvalZ n : {morph valA : x / x *+ n >-> (x ^+ n)%g}.
proof: Proof. by move=> u; rewrite /= morphX ?inE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype bigop ssralg finset fingroup) mathcomp(morphism perm finalg action gproduct commutator) mathcomp(cyclic)