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_3: R_4(z_3) or ~T(z_3). forall z_3: R_4(z_3) -> T(z_3). exists z_3: T(z_3) -> R_4(z_3). forall z_3: ~T(z_3).
forall z_3: ~R_4(z_3) can be inferred via the universal modus tollens rule. forall z_3: T(z_3) -> R_4(z_3) can be inferred via the universal rewriting rule. exists z_3: T(z_3) <-> R_4(z_3) can be inferred via the existential biconditional introduction rule. exists z_3: R_4(z_3) <-> T(z_3) can be inferred via the existential biconditional introduction rule.