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_7. ~q. p_7 <-> q_7. p -> q.
~p can be inferred via the modus tollens rule. ~p_7 and ~q can be inferred via the conjunction rule. ~q and ~p_7 can be inferred via the conjunction rule. p_7 -> q_7 can be inferred via the biconditional elimination rule. q_7 -> p_7 can be inferred via the biconditional elimination rule. ~q_7 can be inferred via the biconditional elimination rule.