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(x, f(y, a)) → f(f(a, a), f(f(x, a), y))

Q is empty.


QTRS

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

f(x, f(y, a)) → f(f(a, a), f(f(x, a), y))

Q is empty.