proposition: Lemma mem_Zp x : p > 1 -> x \in Zp.
proof: Proof. by rewrite /Zp => ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool choice eqtype ssrnat seq div) mathcomp(fintype bigop finset prime fingroup) mathcomp(ssralg finalg countalg)