proposition: Lemma autact_is_groupAction : is_groupAction G aut_action.
proof: Proof. by move=> a Aa /=; rewrite autactK. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat div seq) mathcomp(fintype bigop finset fingroup morphism perm) mathcomp(automorphism quotient)