What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? q_3 -> q_1. q_1 -> q_3. ~r_1. r_1 <-> q_3.
q_3 <-> q_1. q_1 <-> q_3. r_1 -> q_3. q_3 -> r_1. ~q_3.