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: Q(z) -> W(z). Q(f) <-> W(f).
Q(f) -> W(f) can be inferred via the biconditional elimination rule. W(f) -> Q(f) can be inferred via the biconditional elimination rule.