Consider the following premises. forall x_9: T(x_9) <-> Q_9(x_9). exists x_9: T(x_9) <-> Q_9(x_9). Can we infer forall x_9: ~(T(x_9) <-> Q_9(x_9)) from them? If possible, name the inference rules being used at each step.
That contradicts the premises. Therefore the answer is no.