Input TRS:
    1: active(f(X)) -> mark(g(h(f(X))))
    2: active(f(X)) -> f(active(X))
    3: active(h(X)) -> h(active(X))
    4: f(mark(X)) -> mark(f(X))
    5: h(mark(X)) -> mark(h(X))
    6: proper(f(X)) -> f(proper(X))
    7: proper(g(X)) -> g(proper(X))
    8: proper(h(X)) -> h(proper(X))
    9: f(ok(X)) -> ok(f(X))
    10: g(ok(X)) -> ok(g(X))
    11: h(ok(X)) -> ok(h(X))
    12: top(mark(X)) -> top(proper(X))
    13: top(ok(X)) -> top(active(X))
Number of Rules: 13
Direct QTKBOS ... failed.