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: w or s. s <-> t_2. ~t_2.
~s -> w can be inferred via the rewriting rule. s -> t_2 can be inferred via the biconditional elimination rule. t_2 -> s can be inferred via the biconditional elimination rule. ~s can be inferred via the biconditional elimination rule.