∀ {R : Type u_1} {V : Type u_2} [inst : CommRing R] [inst_1 : AddCommGroup V] [inst_2 : Module R V],
  VertexOperator.ncoeff = { toFun := fun A n => HVertexOperator.coeff A (-n - 1), map_add' := ⋯, map_smul' := ⋯ }