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: t -> t_3. ~w. t_3 -> t. t_3 -> w.
~t_3 can be inferred via the modus tollens rule. t -> w can be inferred via the transitivity rule. t <-> t_3 can be inferred via the biconditional introduction rule. t_3 <-> t can be inferred via the biconditional introduction rule.