Consider the following premises. ~R_12(a_12). forall x_12: R_12(x_12) <-> S_12(x_12). s -> w. w -> S_12(a_12). Can we infer ~s from them?
 From forall x_12: R_12(x_12) <-> S_12(x_12) we can infer R_12(a_12) <-> S_12(a_12). From R_12(a_12) <-> S_12(a_12), ~R_12(a_12) we can infer ~S_12(a_12). From s -> w, w -> S_12(a_12) we can infer s -> S_12(a_12). Finally, from s -> S_12(a_12), ~S_12(a_12) we can infer ~s. Therefore, the answer is yes.