Input TRS:
    1: active(g(X)) -> mark(h(X))
    2: active(c()) -> mark(d())
    3: active(h(d())) -> mark(g(c()))
    4: mark(g(X)) -> active(g(X))
    5: mark(h(X)) -> active(h(X))
    6: mark(c()) -> active(c())
    7: mark(d()) -> active(d())
    8: g(mark(X)) -> g(X)
    9: g(active(X)) -> g(X)
    10: h(mark(X)) -> h(X)
    11: h(active(X)) -> h(X)
Number of Rules: 11
Direct QWPOS(Sum) ... failed.