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_4 <-> q_12. ~q_12.
u_4 -> q_12 can be inferred via the biconditional elimination rule. q_12 -> u_4 can be inferred via the biconditional elimination rule. ~u_4 can be inferred via the biconditional elimination rule.