Input TRS:
    1: f(a(),f(a(),f(a(),f(x,b())))) -> f(f(a(),f(a(),f(a(),x))),b())
    2: f(f(f(a(),x),b()),b()) -> f(f(a(),f(f(x,b()),b())),b())
Number of Rules: 2
Direct QWPOS(max) ... failed.