TRS:
 {          f(x, 0(), 0()) -> s(x),
            f(0(), y, 0()) -> s(y),
            f(0(), 0(), z) -> s(z),
           f(s(0()), y, z) -> f(0(), s(y), s(z)),
        f(s(x), s(y), 0()) -> f(x, y, s(0())),
        f(s(x), 0(), s(z)) -> f(x, s(0()), z),
    f(0(), s(0()), s(0())) -> s(s(0())),
       f(s(x), s(y), s(z)) -> f(x, y, f(s(x), s(y), z)),
   f(0(), s(s(y)), s(0())) -> f(0(), y, s(0())),
   f(0(), s(0()), s(s(z))) -> f(0(), s(0()), z),
  f(0(), s(s(y)), s(s(z))) -> f(0(), y, f(0(), s(s(y)), s(z)))}
 Fail