Consider the following premises. forall x_8: P_8(x_8) -> Q_8(x_8). exists x_8: R_8(x_8) <-> P_8(x_8). forall x_8: Q_8(x_8) -> R_8(x_8). Can we infer forall x_8: ~(R_8(x_8) -> P_8(x_8)) from them? If possible, name the inference rules being used at each step.
That contradicts the premises. Therefore the answer is no.