proposition: Lemma Frobenius_aut_is_multiplicative : multiplicative (Frobenius_aut charRp).
proof: Proof. split=> [x y|]; first exact: Frobenius_autM_comm _ (mulrC _ _). exact: Frobenius_aut1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)