Consider the following premises. forall x_7: P_7(x_7) <-> Q_4(x_7). forall x_7: Q_4(x_7) or Q_7(x_7). exists x_7: P_7(x_7) or ~Q_7(x_7). Can we infer exists x_7: P_7(x_7) or ~Q_7(x_7) from them? If possible, name the inference rules being used at each step.
That is one of the premises. Therefore, the answer is yes.