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_3 -> t. r_3 <-> q_15. ~r_3. ~t.
~w_3 can be inferred via the modus tollens rule. ~r_3 and ~t can be inferred via the conjunction rule. ~t and ~r_3 can be inferred via the conjunction rule. r_3 -> q_15 can be inferred via the biconditional elimination rule. q_15 -> r_3 can be inferred via the biconditional elimination rule. ~q_15 can be inferred via the biconditional elimination rule.