TRS: { lt(0(), s(x)) -> true(), lt(x, 0()) -> false(), lt(s(x), s(y)) -> lt(x, y), fibo(0()) -> fib(0()), fibo(s(0())) -> fib(s(0())), fibo(s(s(x))) -> sum(fibo(s(x)), fibo(x)), fib(0()) -> s(0()), fib(s(0())) -> s(0()), fib(s(s(x))) -> if(true(), 0(), s(s(x)), 0(), 0()), if(true(), c, s(s(x)), a, b) -> if(lt(s(c), s(s(x))), s(c), s(s(x)), b, c), if(false(), c, s(s(x)), a, b) -> sum(fibo(a), fibo(b)), sum(x, 0()) -> x, sum(x, s(y)) -> s(sum(x, y))} Fail