Consider the following premises. For all x_5, if x_5 goes running, then x_5 is not sleeping. For all x_5, if x_5 were a taxi driver, then x_5 is running. For all x_5, if x_5 goes running, then x_5 is a taxi driver. There is at least one x_5 for which x_5 will sleep. Can we infer the following from them? There is at least one x_5 for which x_5 is not a taxi driver.
 From the fact that for all x_5, if x_5 goes running, then x_5 is not sleeping, and that there is at least one x_5 for which x_5 will sleep we can infer that there is at least one x_5 for which x_5 will not go running. From the fact that for all x_5, if x_5 were a taxi driver, then x_5 is running, and that for all x_5, if x_5 goes running, then x_5 is a taxi driver we can infer that for all x_5, x_5 is a taxi driver if and only if x_5 will go running. Finally, from the fact that for all x_5, x_5 is a taxi driver if and only if x_5 will go running, and that there is at least one x_5 for which x_5 will not go running we can infer that there is at least one x_5 for which x_5 is not a taxi driver. Therefore, the answer is yes.