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: P_4(z). forall z: Q_4(z) <-> P_4(z). forall z: S(z).
forall z: P_4(z) and S(z) can be inferred via the universal conjunction rule. forall z: S(z) and P_4(z) can be inferred via the universal conjunction rule. forall z: Q_4(z) -> P_4(z) can be inferred via the universal biconditional elimination rule. forall z: P_4(z) -> Q_4(z) can be inferred via the universal biconditional elimination rule.