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_15 -> w_3. w_3 -> q_15. q_11. ~w_3 -> q. q_15 -> ~q_11.
~q_15 can be inferred via the modus tollens rule. w_3 -> ~q_11 can be inferred via the transitivity rule. q_15 <-> w_3 can be inferred via the biconditional introduction rule. w_3 <-> q_15 can be inferred via the biconditional introduction rule.