proposition: Lemma gal_cap U V : 'Gal(V / U) = 'Gal(V / U :&: V).
proof: Proof. by rewrite /galoisG -capvA capvv. 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)