Consider the following premises. s <-> S_7(d). forall x_7: R_7(x_7) <-> S_7(x_7). ~R_7(d). Can we infer s from them?
 From forall x_7: R_7(x_7) <-> S_7(x_7) we can infer R_7(d) <-> S_7(d). From R_7(d) <-> S_7(d), ~R_7(d) we can infer ~S_7(d). Finally, from s <-> S_7(d), ~S_7(d) we can infer ~s, which contradicts s. Therefore, the answer is no.