Consider the following premises. ~q. forall x_7: R_7(x_7) <-> S_7(x_7). q <-> S_7(a_7). Can we infer ~R_7(a_7) from them?
 From forall x_7: R_7(x_7) <-> S_7(x_7) we can infer R_7(a_7) <-> S_7(a_7). From q <-> S_7(a_7), ~q we can infer ~S_7(a_7). Finally, from R_7(a_7) <-> S_7(a_7), ~S_7(a_7) we can infer ~R_7(a_7). Therefore, the answer is yes.