Consider the following premises. forall x_9: Q_9(x_9) -> U(x_9). forall x_9: Q_9(x_9). forall x_9: U(x_9) -> Q_9(x_9). Can we infer ~R_4(f_4) from them? If possible, name the inference rules being used at each step.
We cannot infer that from the premises. Therefore the answer is no.