Consider the following premises. Richard is not working. David is running. For all x, if x were poor, then x is working. Can we infer the following from them? If we can, name the inference rule being used: Richard is poor.
 From the fact that for all x, if x were poor, then x is working we can infer that if Richard were poor, then Richard is working via universal instantiation. Finally, from the fact that if Richard were poor, then Richard is working, and that Richard is not working we can infer that Richard is not poor via modus tollens, which contradicts that Richard is poor. Therefore, the answer is no.