proposition: Lemma lcn_group_set n G : group_set 'L_n(G).
proof: Proof. by case: n => [|[|n]]; apply: groupP. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(fintype div bigop prime finset fingroup morphism) mathcomp(automorphism quotient commutator gproduct) mathcomp(gfunctor center gseries cyclic)