proposition: Lemma psubgroup1 pi G : pi.-subgroup(G) 1.
proof: Proof. by rewrite /psubgroup sub1G pgroup1. 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)