Consider the following premises. forall x: Q(x) <-> R_4(x). forall x: R_4(x) or ~Q_4(x). Can we infer forall x: Q_4(x) -> Q(x) from them?
 From forall x: R_4(x) or ~Q_4(x) we can infer forall x: Q_4(x) -> R_4(x). From forall x: Q(x) <-> R_4(x) we can infer forall x: R_4(x) -> Q(x). Finally, from forall x: Q_4(x) -> R_4(x), forall x: R_4(x) -> Q(x) we can infer forall x: Q_4(x) -> Q(x). Therefore, the answer is yes.