What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? exists z: U(z) <-> U_1(z). forall z: Q(z) -> U_1(z). forall z: S_3(z) -> U_1(z). forall z: Q(z) or S_3(z).
forall z: U_1(z). exists z: U(z) -> U_1(z). exists z: U_1(z) -> U(z).