proposition: Lemma pgroup_pi G : \pi(G).-group G.
proof: Proof. by rewrite /=; apply: pnat_pi. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(fintype bigop finset prime fingroup morphism) mathcomp(gfunctor automorphism quotient action gproduct) mathcomp(cyclic)