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