proposition: Lemma card_Aut_cycle : #|Aut <[a]>| = totient #[a].
proof: Proof. by rewrite -(card_isog Zp_unit_isog) card_units_Zp. 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)