MAYBE

Problem:
 fib(0()) -> 0()
 fib(s(0())) -> s(0())
 fib(s(s(x))) -> +(fib(s(x)),fib(x))
 +(x,0()) -> x
 +(x,s(y)) -> s(+(x,y))

Proof:
 DP Processor:
  DPs:
   fib#(s(s(x))) -> fib#(x)
   fib#(s(s(x))) -> fib#(s(x))
   fib#(s(s(x))) -> +#(fib(s(x)),fib(x))
   +#(x,s(y)) -> +#(x,y)
  TRS:
   fib(0()) -> 0()
   fib(s(0())) -> s(0())
   fib(s(s(x))) -> +(fib(s(x)),fib(x))
   +(x,0()) -> x
   +(x,s(y)) -> s(+(x,y))
  Open