YES

TRS:

  fib(0()) -> 0()
  fib(s(0())) -> s(0())
  fib(s(s(x))) -> +(fib(s(x)),fib(x))

linear polynomial interpretations on N:

  fib_A(x1) = 1
  fib#_A(x1) = 3
  0_A = 1
  0#_A = 0
  s_A(x1) = 1
  s#_A(x1) = 1
  +_A(x1,x2) = 0
  +#_A(x1,x2) = 2

precedence:

  fib > s > 0 = +