Consider the following premises. forall x_7: Q_3(x_7) <-> S_7(x_7). S_7(a_7) -> t. ~t. Can we infer ~Q_3(a_7) from them?
 From forall x_7: Q_3(x_7) <-> S_7(x_7) we can infer Q_3(a_7) <-> S_7(a_7). From S_7(a_7) -> t, ~t we can infer ~S_7(a_7). Finally, from Q_3(a_7) <-> S_7(a_7), ~S_7(a_7) we can infer ~Q_3(a_7). Therefore, the answer is yes.