What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? w_3 or u_4. q_13 <-> w_3. ~p_13. p_13 <-> q_13.
q_13 -> w_3. p_13 -> q_13. w_3 -> q_13. q_13 -> p_13. ~q_13.