Consider the following premises. forall y: S_4(y) -> Q_1(y). forall y: Q_1(y) -> U_2(y). exists y: S_4(y) or W(y). forall y: W(y) -> Q_1(y). Can we infer forall y: ~U_2(y) from them?
 From forall y: S_4(y) -> Q_1(y), forall y: W(y) -> Q_1(y), exists y: S_4(y) or W(y) we can infer exists y: Q_1(y). Finally, from forall y: Q_1(y) -> U_2(y), exists y: Q_1(y) we can infer exists y: U_2(y), which contradicts forall y: ~U_2(y). Therefore, the answer is no.