
theorem
  for V, W being non empty ModuleStr over INT.Ring, f being FrFunctional of V
  holds FrFormFunctional(f,0FrFunctional(W)) = NulFrForm(V,W)
  proof
    let V, W be non empty ModuleStr over INT.Ring, f be FrFunctional of V;
    now
      let v be Vector of V, y be Vector of W;
      thus FrFormFunctional(f,0FrFunctional(W)).(v,y) = 0.INT.Ring by HTh20
      .= NulFrForm(V,W).(v,y) by FUNCOP_1:70;
    end;
    hence thesis;
  end;
