Input TRS:
    1: a(0(),b(0(),x)) -> b(0(),a(0(),x))
    2: a(0(),x) -> b(0(),b(0(),x))
    3: a(0(),a(1(),a(x,y))) -> a(1(),a(0(),a(x,y)))
    4: b(0(),a(1(),a(x,y))) -> b(1(),a(0(),a(x,y)))
    5: a(0(),a(x,y)) -> a(1(),a(1(),a(x,y)))
Number of Rules: 5
Direct QWPOS(Sum) ... failed.