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: w_4 -> q_13. w <-> q_13. w_4.
q_13 can be inferred via the modus ponens rule. w -> q_13 can be inferred via the biconditional elimination rule. q_13 -> w can be inferred via the biconditional elimination rule.