theorem BLTh36:
  for V, W being Z_Module, v being Vector of V, w, t being Vector of W,
  f being additiveFAF homogeneousFAF Form of V,W
  holds f.(v,w-t) = f.(v,w) - f.(v,t)
  proof
    let V, W be Z_Module, v be Vector of V, y, z be Vector of W,
    f be additiveFAF homogeneousFAF Form of V,W;
    thus f.(v,y-z) = f.(v,y) + f.(v,-z) by BLTh27
    .= f.(v,y) + f.(v,(-1.INT.Ring)* z) by ZMODUL01:2
    .= f.(v,y) + (-1.INT.Ring)*f.(v,z) by BLTh32
    .= f.(v,y) - f.(v,z);
  end;
