Consider the following premises. For all x_13, if x_13 drinks water, then x_13 is writing a letter. For all x_13, if x_13 were an artist, then x_13 is taking a plane. For all x_13, if x_13 sleeps, then x_13 is taking a plane. For all x_13, x_13 will drink water. For all x_13, x_13 is an artist or x_13 will sleep. Can we infer the following from them? If we can, name the inference rule being used: Jessica is writing a letter.
 From the fact that for all x_13, if x_13 were an artist, then x_13 is taking a plane, that for all x_13, if x_13 sleeps, then x_13 is taking a plane, and that for all x_13, x_13 is an artist or x_13 will sleep we can infer that for all x_13, x_13 will take a plane via universal disjunction elimination. From the fact that for all x_13, x_13 will drink water, and that for all x_13, x_13 will take a plane we can infer that for all x_13, x_13 will drink water and x_13 will take a plane via universal conjunction. From the fact that for all x_13, x_13 will drink water and x_13 will take a plane we can infer that for all x_13, x_13 will drink water via universal simplification. From the fact that for all x_13, if x_13 drinks water, then x_13 is writing a letter, and that for all x_13, x_13 will drink water we can infer that for all x_13, x_13 will write a letter via universal modus ponens. Finally, from the fact that for all x_13, x_13 will write a letter we can infer that Jessica is writing a letter via universal instantiation. Therefore, the answer is yes.