Consider the following premises. For all x_10, x_10 is an electrician if and only if x_10 is an office clerk. There is at least one x_10 for which x_10 is not an electrician. For all x_10, x_10 is an office clerk if and only if x_10 will work. Can we infer the following from them? There is at least one x_10 for which x_10 will not work.
 From the fact that for all x_10, x_10 is an electrician if and only if x_10 is an office clerk, and that there is at least one x_10 for which x_10 is not an electrician we can infer that there is at least one x_10 for which x_10 is not an office clerk. From the fact that for all x_10, x_10 is an office clerk if and only if x_10 will work we can infer that for all x_10, if x_10 works, then x_10 is an office clerk. Finally, from the fact that for all x_10, if x_10 works, then x_10 is an office clerk, and that there is at least one x_10 for which x_10 is not an office clerk we can infer that there is at least one x_10 for which x_10 will not work. Therefore, the answer is yes.