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) -> ~U_1(z). forall z: U_1(z). forall z: W(z) <-> S(z).
forall z: ~W(z) can be inferred via the universal modus tollens rule. forall z: W(z) -> S(z) can be inferred via the universal biconditional elimination rule. forall z: S(z) -> W(z) can be inferred via the universal biconditional elimination rule.