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_13. q. s <-> q_13.
q_13 and q can be inferred via the conjunction rule. q and q_13 can be inferred via the conjunction rule. s -> q_13 can be inferred via the biconditional elimination rule. q_13 -> s can be inferred via the biconditional elimination rule.