Consider the following premises. forall y: W(y) or U_2(y). forall y: ~S_2(y). forall y: ~W(y) or U(y). forall y: U_2(y) <-> S_2(y). Can we infer U(e_3) from them?
 From forall y: U_2(y) <-> S_2(y), forall y: ~S_2(y) we can infer forall y: ~U_2(y). From forall y: W(y) or U_2(y), forall y: ~W(y) or U(y) we can infer forall y: U_2(y) or U(y). From forall y: U_2(y) or U(y), forall y: ~U_2(y) we can infer forall y: U(y). Finally, from forall y: U(y) we can infer U(e_3). Therefore, the answer is yes.