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: ~q_17. q_4. t <-> q_17. w -> ~q_4.
~w can be inferred via the modus tollens rule. ~q_17 and q_4 can be inferred via the conjunction rule. q_4 and ~q_17 can be inferred via the conjunction rule. t -> q_17 can be inferred via the biconditional elimination rule. q_17 -> t can be inferred via the biconditional elimination rule. ~t can be inferred via the biconditional elimination rule.