Consider the following premises. forall x_18: W(x_18) or P(x_18). exists x_18: W(x_18) <-> Q_18(x_18). forall x_18: Q_1(x_18). forall x_18: ~Q_18(x_18). Can we infer forall x_18: ~Q_1(x_18) from them? If possible, name the inference rules being used at each step.
That contradicts the premises. Therefore the answer is no.