TRS:
 {    +(0(), y) -> y,
     +(s(x), y) -> s(+(x, y)),
      -(0(), y) -> 0(),
      -(x, 0()) -> x,
  -(s(x), s(y)) -> -(x, y)}
 LMPO:
  Quasi-Precedence:
  empty
  
Normal:
   pi(-) = [1,2], pi(+) = [1,2]
  
Safe:
   
  
Predicative System:
   {      +(0(),y;) -> y,
        +(s(x;),y;) -> s(+(x,y;);),
          -(0(),y;) -> 0(),
          -(x,0();) -> x,
    -(s(x;),s(y;);) -> -(x,y;)}
  

   
  

  Qed