Consider the following premises. For all x_19, x_19 will read a book if and only if x_19 is a mechanic. For all x_19, if x_19 were a janitor, then x_19 is reading a book. For all x_19, x_19 is a mechanic or x_19 is a janitor. For all x_19, x_19 is a nurse or x_19 is a bartender. There is at least one x_19 for which x_19 is not a nurse. Can we infer the following from them? There is at least one x_19 for which x_19 is a bartender.
 From the fact that for all x_19, x_19 will read a book if and only if x_19 is a mechanic we can infer that for all x_19, if x_19 were a mechanic, then x_19 is reading a book. Finally, from the fact that for all x_19, x_19 is a nurse or x_19 is a bartender, and that there is at least one x_19 for which x_19 is not a nurse we can infer that there is at least one x_19 for which x_19 is a bartender. Therefore, the answer is yes.