What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_3: T(x_3) -> U_4(x_3). forall x_3: ~R_2(x_3). forall x_3: U_4(x_3) -> T(x_3). exists x_3: U_4(x_3) <-> R_2(x_3).
forall x_3: T(x_3) <-> U_4(x_3). forall x_3: U_4(x_3) <-> T(x_3). exists x_3: U_4(x_3) -> R_2(x_3). exists x_3: R_2(x_3) -> U_4(x_3). exists x_3: ~U_4(x_3).