Consider the following premises. Q_10(a_7) -> W_3(a_7). forall x_10: W_3(x_10) <-> Q_10(x_10). ~W_3(a_7). Can we infer Q_10(a_7) from them? If possible, name the inference rules being used at each step.
 From forall x_10: W_3(x_10) <-> Q_10(x_10) we can infer forall x_10: W_3(x_10) -> Q_10(x_10) via universal biconditional elimination. From forall x_10: W_3(x_10) -> Q_10(x_10) we can infer W_3(a_7) -> Q_10(a_7) via universal instantiation. From W_3(a_7) -> Q_10(a_7), Q_10(a_7) -> W_3(a_7) we can infer W_3(a_7) <-> Q_10(a_7) via biconditional introduction. Finally, from W_3(a_7) <-> Q_10(a_7), ~W_3(a_7) we can infer ~Q_10(a_7) via biconditional elimination, which contradicts Q_10(a_7). Therefore, the answer is no.