Consider the following premises. forall y: R_2(y) or U(y). forall y: U(y) -> T(y). exists y: ~R_2(y) or Q_4(y). forall y: Q_4(y) <-> T(y). Can we infer forall y: ~T(y) from them? If possible, name the inference rules being used at each step.
 From forall y: R_2(y) or U(y), exists y: ~R_2(y) or Q_4(y) we can infer exists y: U(y) or Q_4(y) via existential resolution. From forall y: Q_4(y) <-> T(y) we can infer forall y: Q_4(y) -> T(y) via universal biconditional elimination. Finally, from forall y: U(y) -> T(y), forall y: Q_4(y) -> T(y), exists y: U(y) or Q_4(y) we can infer exists y: T(y) via existential disjunction elimination, which contradicts forall y: ~T(y). Therefore, the answer is no.