Consider the following premises. For all x_11, if x_11 were excited, then x_11 is a bartender. For all x_11, x_11 is excited or x_11 will go running. For all x_11, if x_11 writes a letter, then x_11 is a scientist. For all x_11, if x_11 were a scientist, then x_11 is a bartender. For all x_11, x_11 will go running if and only if x_11 will write a letter. Can we infer the following from them? There is at least one x_11 for which x_11 is not a bartender.
 From the fact that for all x_11, x_11 will go running if and only if x_11 will write a letter we can infer that for all x_11, if x_11 goes running, then x_11 is writing a letter. From the fact that for all x_11, if x_11 writes a letter, then x_11 is a scientist, and that for all x_11, if x_11 were a scientist, then x_11 is a bartender we can infer that for all x_11, if x_11 writes a letter, then x_11 is a bartender. From the fact that for all x_11, if x_11 goes running, then x_11 is writing a letter, and that for all x_11, if x_11 writes a letter, then x_11 is a bartender we can infer that for all x_11, if x_11 goes running, then x_11 is a bartender. Finally, from the fact that for all x_11, if x_11 were excited, then x_11 is a bartender, that for all x_11, if x_11 goes running, then x_11 is a bartender, and that for all x_11, x_11 is excited or x_11 will go running we can infer that for all x_11, x_11 is a bartender, which contradicts that There is at least one x_11 for which x_11 is not a bartender. Therefore, the answer is no.