proposition: Lemma formDl u v w : '[u + v, w] = '[u, w] + '[v, w].
proof: Proof. by rewrite /form !mulmxDl mxE. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg fingroup zmodp poly ssrnum) mathcomp(matrix mxalgebra vector falgebra ssrnum algC algnum) mathcomp(fieldext) mathcomp(vector)