Consider the following premises. forall x_8: P_8(x_8). forall x_8: P_8(x_8) -> Q_8(x_8). forall x_8: ~Q_8(x_8) or R_5(x_8). ~P(a_3). 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.