Consider the following premises. R(a_5) -> Q_1(a_5). forall y_4: R(y_4) or ~Q_1(y_4). Can we infer R(a_5) <-> Q_1(a_5) from them? If possible, name the inference rules being used at each step.
 From forall y_4: R(y_4) or ~Q_1(y_4) we can infer forall y_4: Q_1(y_4) -> R(y_4) via universal rewriting. From forall y_4: Q_1(y_4) -> R(y_4) we can infer Q_1(a_5) -> R(a_5) via universal instantiation. Finally, from R(a_5) -> Q_1(a_5), Q_1(a_5) -> R(a_5) we can infer R(a_5) <-> Q_1(a_5) via biconditional introduction. Therefore, the answer is yes.