What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? q_15 -> w_3. ~w_3 -> q. q_11. q_15 -> ~q_11. w_3 -> q_15.
~q_15. w_3 -> ~q_11. q_15 <-> w_3. w_3 <-> q_15.