Consider the following premises. forall y: ~U_3(y) or R_2(y). forall y: U_3(y) or S_2(y). forall y: ~S_2(y) or W_1(y). R_2(a_12) -> u. W_1(a_12) -> u. Can we infer u or t_3 from them?
 From forall y: U_3(y) or S_2(y), forall y: ~U_3(y) or R_2(y) we can infer forall y: S_2(y) or R_2(y). From forall y: S_2(y) or R_2(y), forall y: ~S_2(y) or W_1(y) we can infer forall y: R_2(y) or W_1(y). From forall y: R_2(y) or W_1(y) we can infer R_2(a_12) or W_1(a_12). From R_2(a_12) -> u, W_1(a_12) -> u, R_2(a_12) or W_1(a_12) we can infer u. Finally, from u we can infer u or t_3. Therefore, the answer is yes.