Consider the following premises. For all x_9, x_9 is not a janitor. There is at least one x_9 for which x_9 will make tea if and only if x_9 is a janitor. For all x_9, x_9 will make tea. Can we infer the following from them? There is at least one x_9 for which x_9 will work.
 From the fact that for all x_9, x_9 will make tea we can infer that for all x_9, x_9 will make tea or x_9 will work. From the fact that there is at least one x_9 for which x_9 will make tea if and only if x_9 is a janitor, and that for all x_9, x_9 is not a janitor we can infer that there is at least one x_9 for which x_9 will not make tea. Finally, from the fact that for all x_9, x_9 will make tea or x_9 will work, and that there is at least one x_9 for which x_9 will not make tea we can infer that there is at least one x_9 for which x_9 will work. Therefore, the answer is yes. Notice, however, that the premises were contradictory, so we can infer anything from them.