Consider the following premises. There is at least one x for which if x were a politician, then x is reading a book. For all x, if x drinks water, then x is writing a letter. For all x, x is a politician or x is a musician. For all x, if x were a musician, then x is drinking water. For all x, if x reads a book, then x is writing a letter. Can we infer the following from them? There is at least one x for which x will write a letter.
 From the fact that there is at least one x for which if x were a politician, then x is reading a book, and that for all x, if x reads a book, then x is writing a letter we can infer that there is at least one x for which if x were a politician, then x is writing a letter. From the fact that for all x, if x were a musician, then x is drinking water, and that for all x, if x drinks water, then x is writing a letter we can infer that for all x, if x were a musician, then x is writing a letter. Finally, from the fact that there is at least one x for which if x were a politician, then x is writing a letter, that for all x, if x were a musician, then x is writing a letter, and that for all x, x is a politician or x is a musician we can infer that there is at least one x for which x will write a letter. Therefore, the answer is yes.