Input TRS:
    1: average(s(x),y) -> average(x,s(y))
    2: average(x,s(s(s(y)))) -> s(average(s(x),y))
    3: average(0(),0()) -> 0()
    4: average(0(),s(0())) -> 0()
    5: average(0(),s(s(0()))) -> s(0())
Number of Rules: 5
Direct POLO(Sum) ... failed.