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: p_6 -> q_3. q_3 -> p_6. q_3 -> q. q -> q_3. ~q.
~q_3 can be inferred via the modus tollens rule. p_6 -> q can be inferred via the transitivity rule. q -> p_6 can be inferred via the transitivity rule. p_6 <-> q_3 can be inferred via the biconditional introduction rule. q_3 <-> p_6 can be inferred via the biconditional introduction rule. q_3 <-> q can be inferred via the biconditional introduction rule. q <-> q_3 can be inferred via the biconditional introduction rule.