Consider the following premises. forall x_9: P_9(x_9). p -> ~P_9(a_9). Can we infer ~p from them? If possible, name the inference rules being used at each step.
 From forall x_9: P_9(x_9) we can infer P_9(a_9) via universal instantiation. Finally, from p -> ~P_9(a_9), P_9(a_9) we can infer ~p via modus tollens. Therefore, the answer is yes.