proposition: Lemma Zp_unit_isom : isom (units_Zp #[a]) (Aut <[a]>) Zp_unitm.
proof: Proof. by apply/isomP; rewrite ?injm_Zp_unitm ?im_Zp_unitm. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice div) mathcomp(fintype bigop prime finset fingroup morphism) mathcomp(perm automorphism quotient gproduct ssralg) mathcomp(finalg zmodp poly)