What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? p_2 <-> r_3. r_4. p_2 <-> q_13. ~q_13.
r_4 and ~q_13. ~q_13 and r_4. p_2 -> r_3. p_2 -> q_13. r_3 -> p_2. q_13 -> p_2. ~p_2.