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)),
        p(s(x)) -> x,
        f(s(x)) -> f(-(p(*(s(x), s(x))), *(s(x), s(x))))}
 Fail