Consider the following premises. There is at least one x_6 for which if x_6 writes a letter, then x_6 is a server. For all x_6, x_6 is not a cashier. For all x_6, if x_6 were a server, then x_6 is writing a letter. For all x_6, if x_6 were a server, then x_6 is a cashier. Can we infer the following from them? For all x_6, x_6 will write a letter.
 From the fact that for all x_6, if x_6 were a server, then x_6 is writing a letter, and that there is at least one x_6 for which if x_6 writes a letter, then x_6 is a server we can infer that there is at least one x_6 for which x_6 is a server if and only if x_6 will write a letter. From the fact that for all x_6, if x_6 were a server, then x_6 is a cashier, and that for all x_6, x_6 is not a cashier we can infer that for all x_6, x_6 is not a server. Finally, from the fact that there is at least one x_6 for which x_6 is a server if and only if x_6 will write a letter, and that for all x_6, x_6 is not a server we can infer that there is at least one x_6 for which x_6 will not write a letter, which contradicts that For all x_6, x_6 will write a letter. Therefore, the answer is no.