Consider the following premises. p. ~R_3(a_11). forall x: R_3(x) <-> U_1(x). Can we infer U_1(a_11) from them?
 From forall x: R_3(x) <-> U_1(x) we can infer R_3(a_11) <-> U_1(a_11). Finally, from R_3(a_11) <-> U_1(a_11), ~R_3(a_11) we can infer ~U_1(a_11), which contradicts U_1(a_11). Therefore, the answer is no.