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_3 <-> w. q_3 -> t. t -> w.
q_3 -> w can be inferred via the transitivity rule. q_3 -> w can be inferred via the biconditional elimination rule. w -> q_3 can be inferred via the biconditional elimination rule.