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_2(z). forall z: Q(z) or S_2(z). forall z: S_2(z) -> R_1(z). forall z: Q(z) <-> R_1(z).
forall z: R_1(z) <-> S_2(z) can be inferred via the universal biconditional introduction rule. forall z: S_2(z) <-> R_1(z) can be inferred via the universal biconditional introduction rule. forall z: Q(z) -> R_1(z) can be inferred via the universal biconditional elimination rule. forall z: R_1(z) -> Q(z) can be inferred via the universal biconditional elimination rule.