TRS:
 {  exp(x, 0()) -> s(0()),
   exp(x, s(y)) -> *(x, exp(x, y)),
      *(0(), y) -> 0(),
     *(s(x), y) -> +(y, *(x, y)),
      -(0(), y) -> 0(),
      -(x, 0()) -> x,
  -(s(x), s(y)) -> -(x, y)}
 MPO:
  Prec:
   * > +, 
   exp > *, 
   exp > s
   empty
  Strict:
   {}
   Weak:
    {}
  Qed