Input TRS:
    1: f(a()) -> f(c(a()))
    2: f(c(X)) -> X
    3: f(c(a())) -> f(d(b()))
    4: f(a()) -> f(d(a()))
    5: f(d(X)) -> X
    6: f(c(b())) -> f(d(a()))
    7: e(g(X)) -> e(X)
Number of Rules: 7
Direct POLO(Pol) ... failed.