What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_3: U(x_3) or T(x_3). forall x_3: U(x_3) -> T_4(x_3). forall x_3: U_4(x_3) -> ~T(x_3). exists x_3: ~T_4(x_3).
exists x_3: ~U(x_3).