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, b) → f(a, c)
f(c, d) → f(b, d)

Q is empty.


QTRS

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

f(a, b) → f(a, c)
f(c, d) → f(b, d)

Q is empty.