Consider the following premises. There is at least one x_14 for which x_14 is an electrician if and only if x_14 is sad. For all x_14, x_14 is a writer. For all x_14, x_14 is sad. Can we infer the following from them? There is at least one x_14 for which x_14 is an electrician and x_14 is a writer.
 From the fact that there is at least one x_14 for which x_14 is an electrician if and only if x_14 is sad we can infer that there is at least one x_14 for which if x_14 were sad, then x_14 is an electrician. From the fact that there is at least one x_14 for which if x_14 were sad, then x_14 is an electrician, and that for all x_14, x_14 is sad we can infer that there is at least one x_14 for which x_14 is an electrician. Finally, from the fact that there is at least one x_14 for which x_14 is an electrician, and that for all x_14, x_14 is a writer we can infer that there is at least one x_14 for which x_14 is an electrician and x_14 is a writer. Therefore, the answer is yes.