What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? exists z: P(z) or W(z). forall z: S_1(z) or ~W(z). forall z: S_1(z) <-> P(z).
forall z: W(z) -> S_1(z). forall z: S_1(z) -> P(z). forall z: P(z) -> S_1(z).