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_3 -> w. ~w. w -> t_3. w -> t_3.
~t_3 can be inferred via the modus tollens rule. t_3 <-> w can be inferred via the biconditional introduction rule. t_3 <-> w can be inferred via the biconditional introduction rule. w <-> t_3 can be inferred via the biconditional introduction rule. w <-> t_3 can be inferred via the biconditional introduction rule.