Consider the following premises. forall y: R(y) <-> Q(y). forall y: Q(y) or ~U_1(y). exists y: Q(y) -> U_1(y). forall y: ~R(y). Can we infer exists y: ~U_1(y) from them?
 From forall y: Q(y) or ~U_1(y) we can infer forall y: U_1(y) -> Q(y). From forall y: R(y) <-> Q(y), forall y: ~R(y) we can infer forall y: ~Q(y). From exists y: Q(y) -> U_1(y), forall y: U_1(y) -> Q(y) we can infer exists y: Q(y) <-> U_1(y). Finally, from exists y: Q(y) <-> U_1(y), forall y: ~Q(y) we can infer exists y: ~U_1(y). Therefore, the answer is yes.