Consider the following premises. For all x_6, if x_6 were a server, then x_6 is cooking. Barbara is a server or Joseph is an office clerk. For all x_6, x_6 will not cook. Can we infer the following from them? Joseph is not an office clerk.
 From the fact that for all x_6, if x_6 were a server, then x_6 is cooking, and that for all x_6, x_6 will not cook we can infer that for all x_6, x_6 is not a server. From the fact that for all x_6, x_6 is not a server we can infer that Barbara is not a server. Finally, from the fact that Barbara is a server or Joseph is an office clerk, and that Barbara is not a server we can infer that Joseph is an office clerk, which contradicts that Joseph is not an office clerk. Therefore, the answer is no.