Consider the following premises. forall x: U_4(x) -> T(x). exists x: S_4(x) -> U(x). forall x: T(x) -> U(x). forall x: S_4(x). Can we infer forall x: ~U(x) from them?
 From forall x: U_4(x) -> T(x), forall x: T(x) -> U(x) we can infer forall x: U_4(x) -> U(x). From forall x: S_4(x) we can infer forall x: S_4(x) or U_4(x). Finally, from exists x: S_4(x) -> U(x), forall x: U_4(x) -> U(x), forall x: S_4(x) or U_4(x) we can infer exists x: U(x), which contradicts forall x: ~U(x). Therefore, the answer is no.