Input TRS:
    1: top1(free(x),y) -> top2(check(new(x)),y)
    2: top1(free(x),y) -> top2(new(x),check(y))
    3: top1(free(x),y) -> top2(check(x),new(y))
    4: top1(free(x),y) -> top2(x,check(new(y)))
    5: top2(x,free(y)) -> top1(check(new(x)),y)
    6: top2(x,free(y)) -> top1(new(x),check(y))
    7: top2(x,free(y)) -> top1(check(x),new(y))
    8: top2(x,free(y)) -> top1(x,check(new(y)))
    9: new(free(x)) -> free(new(x))
    10: old(free(x)) -> free(old(x))
    11: new(serve()) -> free(serve())
    12: old(serve()) -> free(serve())
    13: check(free(x)) -> free(check(x))
    14: check(new(x)) -> new(check(x))
    15: check(old(x)) -> old(check(x))
    16: check(old(x)) -> old(x)
Number of Rules: 16
Direct QLPOS ... failed.