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_6. u -> q_6. ~u.
u -> q_6 can be inferred via the biconditional elimination rule. q_6 -> u can be inferred via the biconditional elimination rule. ~q_6 can be inferred via the biconditional elimination rule.