What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: forall z: S(z) -> P_4(z). exists z: U(z). forall z: R(z). forall z: R(z) -> S(z).
forall z: S(z) can be inferred via the universal modus ponens rule. forall z: R(z) -> P_4(z) can be inferred via the universal transitivity rule. exists z: U(z) and R(z) can be inferred via the existential conjunction rule. exists z: R(z) and U(z) can be inferred via the existential conjunction rule.