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