∀ {R : Type u_2} {V : Type u_1} [inst : CommRing R] [inst_1 : AddCommGroup V] [inst_2 : Module R V] (x : R)
  (x_1 : VertexOperator R V),
  (fun n => HVertexOperator.coeff (x • x_1) (-n - 1)) = (RingHom.id R) x • fun n => HVertexOperator.coeff x_1 (-n - 1)