proposition: Lemma cfextprodDr g h1 h2 : g \ox (h1 + h2) = g \ox h1 + g \ox h2.
proof: Proof. Proof using. by rewrite linearD. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg fingroup morphism perm gproduct) mathcomp(ssrnum matrix vector mxalgebra algC) mathcomp(classfun character mxrepresentation) tools ordcast partition sorted permcomp cycles cycletype permcent