proposition: Lemma gal_kHom K E x : (K <= E)%VS -> (x \in 'Gal(E / K)) = kHom K E x.
proof: Proof. by move/gal_kAut->; rewrite /kAut limg_gal eqxx andbT. 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)