Consider the following premises. forall x_18: P_18(x_18). P_18(a_18) -> r_2. Can we infer r_2 or q from them? If possible, name the inference rules being used at each step.
 From forall x_18: P_18(x_18) we can infer P_18(a_18) via universal instantiation. From P_18(a_18) -> r_2, P_18(a_18) we can infer r_2 via modus ponens. Finally, from r_2 we can infer r_2 or q via addition. Therefore, the answer is yes.