What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? U_3(d). forall z_3: T_1(z_3) <-> U_3(z_3). forall z: R(z).
exists x: U_3(x). forall z_3: T_1(z_3) -> U_3(z_3). forall z_3: U_3(z_3) -> T_1(z_3).