Consider the following premises. u_2 -> R_10(a_10). forall x_10: ~R_10(x_10). u_2 or ~t. Can we infer ~t from them?
 From u_2 or ~t we can infer t -> u_2. From forall x_10: ~R_10(x_10) we can infer ~R_10(a_10). From u_2 -> R_10(a_10), ~R_10(a_10) we can infer ~u_2. Finally, from t -> u_2, ~u_2 we can infer ~t. Therefore, the answer is yes.