Termination w.r.t. Q of the following Term Rewriting System could not be shown:

Q restricted rewrite system:
The TRS R consists of the following rules:

f(a, f(b, f(a, x))) → f(a, f(b, f(b, f(a, x))))
f(b, f(b, f(b, x))) → f(b, f(b, x))

Q is empty.


QTRS

Q restricted rewrite system:
The TRS R consists of the following rules:

f(a, f(b, f(a, x))) → f(a, f(b, f(b, f(a, x))))
f(b, f(b, f(b, x))) → f(b, f(b, x))

Q is empty.