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: exists z_3: S_4(z_3) <-> T_1(z_3). forall z_3: S_4(z_3) -> T_3(z_3). forall z_3: T_3(z_3) -> T_1(z_3).
forall z_3: S_4(z_3) -> T_1(z_3) can be inferred via the universal transitivity rule. exists z_3: S_4(z_3) -> T_1(z_3) can be inferred via the existential biconditional elimination rule. exists z_3: T_1(z_3) -> S_4(z_3) can be inferred via the existential biconditional elimination rule.