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: exists z: Q(z) -> S(z). forall z: W(z) -> Q(z). forall z: ~U_4(z). forall z: U_4(z) or W(z).
exists z: W(z) -> S(z) can be inferred via the existential transitivity rule. forall z: W(z) can be inferred via the universal disjunctive syllogism rule.