Consider the following premises. u_4 <-> R_15(a_4). S_15(a_4) <-> q_9. forall x_15: R_15(x_15) -> S_15(x_15). ~q_9. Can we infer ~u_4 from them?
 From forall x_15: R_15(x_15) -> S_15(x_15) we can infer R_15(a_4) -> S_15(a_4). From S_15(a_4) <-> q_9, ~q_9 we can infer ~S_15(a_4). From R_15(a_4) -> S_15(a_4), ~S_15(a_4) we can infer ~R_15(a_4). Finally, from u_4 <-> R_15(a_4), ~R_15(a_4) we can infer ~u_4. Therefore, the answer is yes.