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: R_1(z) -> S(z). forall z: ~S(z). forall z: S(z) -> R_1(z). forall z: P_3(z) <-> R_1(z).
forall z: ~R_1(z) can be inferred via the universal modus tollens rule. forall z: R_1(z) <-> S(z) can be inferred via the universal biconditional introduction rule. forall z: S(z) <-> R_1(z) can be inferred via the universal biconditional introduction rule. forall z: P_3(z) -> R_1(z) can be inferred via the universal biconditional elimination rule. forall z: R_1(z) -> P_3(z) can be inferred via the universal biconditional elimination rule.