Consider the following premises. ~R(a_12). S_12(a_12) <-> R(a_12). forall x_12: R(x_12) -> S_12(x_12). Can we infer S_12(a_12) from them?
 From forall x_12: R(x_12) -> S_12(x_12) we can infer R(a_12) -> S_12(a_12). From S_12(a_12) <-> R(a_12) we can infer S_12(a_12) -> R(a_12). From R(a_12) -> S_12(a_12), S_12(a_12) -> R(a_12) we can infer R(a_12) <-> S_12(a_12). Finally, from R(a_12) <-> S_12(a_12), ~R(a_12) we can infer ~S_12(a_12), which contradicts S_12(a_12). Therefore, the answer is no.