
theorem
  for V being non empty ModuleStr over INT.Ring, f being FrFunctional of V
  holds f + 0FrFunctional(V) = f
  proof
    let V be non empty ModuleStr over INT.Ring;
    let f be FrFunctional of V;
    now
      let x be Element of V;
      thus (f+0FrFunctional(V)).x = f.x+(0FrFunctional(V)).x by HDef3
      .= f.x+0.F_Real by FUNCOP_1:7
      .= f.x;
    end;
    hence thesis by FUNCT_2:63;
  end;
