MAYBE
Trs:
 {    *(x, 0()) -> 0(),
     *(x, s(y)) -> +(x, *(x, y)),
      +(0(), y) -> y,
     +(s(x), y) -> s(+(x, y)),
  -(s(x), s(y)) -> -(x, y),
      -(x, 0()) -> x,
        f(s(x)) -> f(-(+(*(s(x), s(x)), *(s(x), s(s(s(0()))))), *(s(s(x)), s(s(x)))))}
 Comment:
  We consider a duplicating trs.
  FAIL:
   Open