Consider the following premises. forall x_6: P_6(x_6) and Q_6(x_6). forall x_6: Q_3(x_6). Can we infer Q_3(a_2) from them?
 From forall x_6: P_6(x_6) and Q_6(x_6) we can infer forall x_6: P_6(x_6). From forall x_6: Q_3(x_6), forall x_6: P_6(x_6) we can infer forall x_6: Q_3(x_6) and P_6(x_6). From forall x_6: Q_3(x_6) and P_6(x_6) we can infer Q_3(a_2) and P_6(a_2). Finally, from Q_3(a_2) and P_6(a_2) we can infer Q_3(a_2). Therefore, the answer is yes.