Consider the following premises. There is at least one x_2 for which x_2 will not drink water. For all x_2, x_2 will cook if and only if x_2 is a musician. For all x_2, if x_2 cooks, then x_2 is drinking water. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_2 for which x_2 is not a musician.
 From the fact that for all x_2, if x_2 cooks, then x_2 is drinking water, and that there is at least one x_2 for which x_2 will not drink water we can infer that there is at least one x_2 for which x_2 will not cook via existential modus tollens. Finally, from the fact that for all x_2, x_2 will cook if and only if x_2 is a musician, and that there is at least one x_2 for which x_2 will not cook we can infer that there is at least one x_2 for which x_2 is not a musician via existential biconditional elimination. Therefore, the answer is yes.