Consider the following premises. forall z: ~U_4(z). forall z: U_4(z) or W(z). exists z: Q(z) -> S(z). forall z: W(z) -> Q(z). Can we infer forall z: ~S(z) from them?
 From forall z: W(z) -> Q(z), exists z: Q(z) -> S(z) we can infer exists z: W(z) -> S(z). From forall z: U_4(z) or W(z), forall z: ~U_4(z) we can infer forall z: W(z). Finally, from exists z: W(z) -> S(z), forall z: W(z) we can infer exists z: S(z), which contradicts forall z: ~S(z). Therefore, the answer is no.