Consider the following premises. W(a_15) or ~q_7. forall x_2: W(x_2) -> R_3(x_2). R_3(a_15) -> q_7. Can we infer W(a_15) <-> q_7 from them?
 From forall x_2: W(x_2) -> R_3(x_2) we can infer W(a_15) -> R_3(a_15). From W(a_15) or ~q_7 we can infer q_7 -> W(a_15). From W(a_15) -> R_3(a_15), R_3(a_15) -> q_7 we can infer W(a_15) -> q_7. Finally, from W(a_15) -> q_7, q_7 -> W(a_15) we can infer W(a_15) <-> q_7. Therefore, the answer is yes.