proposition: Lemma center_ncprod0 : 'Z(G_ 0) = G_ 0.
proof: Proof. by apply: center_idP; rewrite (isog_abelian ncprod0) center_abelian. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(fintype bigop finset fingroup morphism perm) mathcomp(automorphism quotient action gproduct gfunctor) mathcomp(cyclic)