Consider the following premises. forall x_9: ~P_9(x_9). forall x_9: P_9(x_9) or Q_1(x_9). forall x_9: P_6(x_9) and Q_6(x_9). Can we infer Q_1(a_2) from them? If possible, name the inference rules being used at each step.
 From forall x_9: P_9(x_9) or Q_1(x_9), forall x_9: ~P_9(x_9) we can infer forall x_9: Q_1(x_9) via universal disjunctive syllogism. From forall x_9: P_6(x_9) and Q_6(x_9) we can infer forall x_9: P_6(x_9) via universal simplification. From forall x_9: Q_1(x_9), forall x_9: P_6(x_9) we can infer forall x_9: Q_1(x_9) and P_6(x_9) via universal conjunction. From forall x_9: Q_1(x_9) and P_6(x_9) we can infer Q_1(a_2) and P_6(a_2) via universal instantiation. Finally, from Q_1(a_2) and P_6(a_2) we can infer Q_1(a_2) via simplification. Therefore, the answer is yes.