proposition: Lemma eq_p_elt pi1 pi2 x : pi1 =i pi2 -> pi1.-elt x = pi2.-elt x.
proof: Proof. by move=> pi12; apply: eq_pnat. 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)