proposition: Lemma afixD1 G : 'Fix_to(G^#) = 'Fix_to(G).
proof: Proof. by rewrite -{2}(setD1K (group1 G)) afixU afix1 setTI. Qed.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat div seq) mathcomp(fintype bigop finset fingroup morphism perm) mathcomp(automorphism quotient)