proposition: Lemma pgroupE pi A : pi.-group A = pi.-nat #|A|.
proof: Proof. by []. 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)