
theorem
  for V, W being non empty ModuleStr over INT.Ring, g being FrFunctional of W
  holds FrFormFunctional(0FrFunctional(V),g) = NulFrForm(V,W)
  proof
    let V, W be non empty ModuleStr over INT.Ring, h be FrFunctional of W;
    now
      let v be Vector of V, y be Vector of W;
      thus FrFormFunctional(0FrFunctional(V),h).(v,y) = 0.INT.Ring by HTh21
      .= NulFrForm(V,W).(v,y) by FUNCOP_1:70;
    end;
    hence thesis;
  end;
