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: W(z). forall z: W(z) -> S(z). exists z: U_3(z).
forall z: S(z) can be inferred via the universal modus ponens rule. exists z: U_3(z) and W(z) can be inferred via the existential conjunction rule. exists z: W(z) and U_3(z) can be inferred via the existential conjunction rule.