proposition: Lemma gal_id E a : (1 : gal_of E)%g a = a.
proof: Proof. by rewrite /gal_repr repr_coset1 id_lfunE. 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)