
theorem Th28:
  for V be non empty ModuleStr over F_Complex, f be Functional of
  V, v be Vector of V holds (FormFunctional(f,f*')).(v,v) = |. f.v .|^2
proof
  let V be non empty ModuleStr over F_Complex, f be Functional of V, v be
  Vector of V;
  set g = FormFunctional(f,f*');
  thus g.(v,v) = f.v * (f*').v by BILINEAR:def 10
    .= f.v * (f.v)*' by Def2
    .= |. f.v .|^2 by Th13;
end;
