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

   
  

  Qed