Consider the following premises. For all x_15, x_15 is an office clerk and x_15 will play squash. For all x_15, if x_15 were an office clerk, then x_15 is writing a letter. For all x_15, if x_15 writes a letter, then x_15 is taking a plane. For all x_15, if x_15 reads a book, then x_15 is drinking water. For all x_15, if x_15 drinks water, then x_15 is not taking a plane. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_15 for which x_15 will read a book.
 From the fact that for all x_15, x_15 is an office clerk and x_15 will play squash we can infer that for all x_15, x_15 is an office clerk via universal simplification. From the fact that for all x_15, if x_15 were an office clerk, then x_15 is writing a letter, and that for all x_15, if x_15 writes a letter, then x_15 is taking a plane we can infer that for all x_15, if x_15 were an office clerk, then x_15 is taking a plane via universal transitivity. From the fact that for all x_15, if x_15 were an office clerk, then x_15 is taking a plane, and that for all x_15, x_15 is an office clerk we can infer that for all x_15, x_15 will take a plane via universal modus ponens. From the fact that for all x_15, if x_15 drinks water, then x_15 is not taking a plane, and that for all x_15, x_15 will take a plane we can infer that for all x_15, x_15 will not drink water via universal modus tollens. Finally, from the fact that for all x_15, if x_15 reads a book, then x_15 is drinking water, and that for all x_15, x_15 will not drink water we can infer that for all x_15, x_15 will not read a book via universal modus tollens, which contradicts that There is at least one x_15 for which x_15 will read a book. Therefore, the answer is no.