Consider the following premises. forall x_15: ~P_15(x_15) or W_4(x_15). forall x_15: P_15(x_15) or Q_15(x_15). s_4 -> ~W_4(d). forall x_15: ~Q_15(x_15). Can we infer ~u 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.