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: p_12 or ~q_12. p_12 <-> w_4. w_4 -> q_12.
q_12 -> p_12 can be inferred via the rewriting rule. p_12 -> w_4 can be inferred via the biconditional elimination rule. w_4 -> p_12 can be inferred via the biconditional elimination rule.