Consider the following premises. For all x, x is not a taxi driver. For all x, x is a taxi driver or x is not fast. For all x, x will take a plane if and only if x is fast. Can we infer the following from them? If we can, name the inference rule being used: For all x, x will not take a plane.
 From the fact that for all x, x is a taxi driver or x is not fast we can infer that for all x, if x were fast, then x is a taxi driver via universal rewriting. From the fact that for all x, if x were fast, then x is a taxi driver, and that for all x, x is not a taxi driver we can infer that for all x, x is not fast via universal modus tollens. Finally, from the fact that for all x, x will take a plane if and only if x is fast, and that for all x, x is not fast we can infer that for all x, x will not take a plane via universal biconditional elimination. Therefore, the answer is yes.