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_1: S(z_1) <-> T(z_1). forall z_1: T(z_1) -> S(z_1). forall z_1: S(z_1) -> T(z_1).
forall z_1: T(z_1) <-> S(z_1) can be inferred via the universal biconditional introduction rule. forall z_1: S(z_1) <-> T(z_1) can be inferred via the universal biconditional introduction rule. forall z_1: S(z_1) -> T(z_1) can be inferred via the universal biconditional elimination rule. forall z_1: T(z_1) -> S(z_1) can be inferred via the universal biconditional elimination rule.