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: forall z: T(z) -> Q(z). Q(b_2) <-> T(b_2).
Q(b_2) -> T(b_2) can be inferred via the biconditional elimination rule. T(b_2) -> Q(b_2) can be inferred via the biconditional elimination rule.