proposition: Lemma ucn_norm : G \subset 'N('Z_n(G)).
proof: Proof. exact: gFnorm. 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)