Consider the following premises. For all x_9, x_9 will work or x_9 is fast. For all x_9, x_9 will not drink water. For all x_9, if x_9 were a mechanic, then x_9 is drinking water. There is at least one x_9 for which x_9 is a mechanic if and only if x_9 will work. Can we infer the following from them? There is at least one x_9 for which x_9 is fast.
 From the fact that for all x_9, if x_9 were a mechanic, then x_9 is drinking water, and that for all x_9, x_9 will not drink water we can infer that for all x_9, x_9 is not a mechanic. From the fact that there is at least one x_9 for which x_9 is a mechanic if and only if x_9 will work, and that for all x_9, x_9 is not a mechanic we can infer that there is at least one x_9 for which x_9 will not work. Finally, from the fact that for all x_9, x_9 will work or x_9 is fast, and that there is at least one x_9 for which x_9 will not work we can infer that there is at least one x_9 for which x_9 is fast. Therefore, the answer is yes.