Input TRS:
    1: f(X) -> if(X,c(),n__f(n__true()))
    2: if(true(),X,Y) -> X
    3: if(false(),X,Y) -> activate(Y)
    4: f(X) -> n__f(X)
    5: true() -> n__true()
    6: activate(n__f(X)) -> f(activate(X))
    7: activate(n__true()) -> true()
    8: activate(X) -> X
Number of Rules: 8
Direct QWPOS(Sum) ... failed.