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_17. p_13 <-> q_4. t_4 -> ~q_17. ~q_4. p_13 <-> q_7.
~t_4 can be inferred via the modus tollens rule. q_17 and ~q_4 can be inferred via the conjunction rule. ~q_4 and q_17 can be inferred via the conjunction rule. p_13 -> q_4 can be inferred via the biconditional elimination rule. p_13 -> q_7 can be inferred via the biconditional elimination rule. q_4 -> p_13 can be inferred via the biconditional elimination rule. q_7 -> p_13 can be inferred via the biconditional elimination rule. ~p_13 can be inferred via the biconditional elimination rule.