proposition: Lemma galNormX n : {morph galNorm U V : a / a ^+ n}.
proof: Proof. move=> a; elim: n => [|n IHn]; first exact: galNorm1. by rewrite !exprS galNormM IHn. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(choice fintype tuple finfun bigop ssralg poly) mathcomp(polydiv finset fingroup morphism quotient perm) mathcomp(action zmodp cyclic matrix mxalgebra vector) mathcomp(falgebra fieldext separable)