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: q_8 -> ~q_2. q_2. p_8 <-> q_8.
~q_8 can be inferred via the modus tollens rule. p_8 -> q_8 can be inferred via the biconditional elimination rule. q_8 -> p_8 can be inferred via the biconditional elimination rule.