Consider the following premises. exists x_6: W(x_6) <-> S(x_6). forall x_6: Q_6(x_6) -> W(x_6). forall x_6: R(x_6) -> Q_6(x_6). Can we infer forall x_6: ~(R(x_6) -> S(x_6)) from them? If possible, name the inference rules being used at each step.
That contradicts the premises. Therefore the answer is no.