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: u <-> q_13. ~u. q.
~u and q can be inferred via the conjunction rule. q and ~u can be inferred via the conjunction rule. u -> q_13 can be inferred via the biconditional elimination rule. q_13 -> u can be inferred via the biconditional elimination rule. ~q_13 can be inferred via the biconditional elimination rule.