proposition: Lemma center_idP A : reflect ('Z(A) = A) (abelian A).
proof: Proof. exact: setIidPl. 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)