Consider the following premises. There is at least one x_16 for which x_16 is not poor. For all x_16, x_16 is curious or x_16 will play tennis. For all x_16, x_16 is a janitor if and only if x_16 is poor. For all x_16, x_16 is a janitor if and only if x_16 is curious. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_16 for which x_16 will play tennis.
 From the fact that for all x_16, x_16 is a janitor if and only if x_16 is poor, and that there is at least one x_16 for which x_16 is not poor we can infer that there is at least one x_16 for which x_16 is not a janitor via existential biconditional elimination. From the fact that for all x_16, x_16 is a janitor if and only if x_16 is curious, and that there is at least one x_16 for which x_16 is not a janitor we can infer that there is at least one x_16 for which x_16 is not curious via existential biconditional elimination. Finally, from the fact that for all x_16, x_16 is curious or x_16 will play tennis, and that there is at least one x_16 for which x_16 is not curious we can infer that there is at least one x_16 for which x_16 will play tennis via existential disjunctive syllogism. Therefore, the answer is yes.