Consider the following premises. s. u_3 <-> S_12(f). forall x_12: R_12(x_12) <-> S_12(x_12). u_3 -> ~s. Can we infer R_12(f) from them?
 From forall x_12: R_12(x_12) <-> S_12(x_12) we can infer R_12(f) <-> S_12(f). From u_3 -> ~s, s we can infer ~u_3. From u_3 <-> S_12(f), ~u_3 we can infer ~S_12(f). Finally, from R_12(f) <-> S_12(f), ~S_12(f) we can infer ~R_12(f), which contradicts R_12(f). Therefore, the answer is no.