Consider the following premises. For all x_14, x_14 is a soldier if and only if x_14 is a writer. For all x_14, x_14 is a soldier or x_14 is not a writer. There is at least one x_14 for which if x_14 were a writer, then x_14 is a soldier. Can we infer the following from them? There is at least one x_14 for which x_14 is a soldier if and only if x_14 is a writer.
 From the fact that for all x_14, x_14 is a soldier if and only if x_14 is a writer we can infer that for all x_14, if x_14 were a soldier, then x_14 is a writer. From the fact that there is at least one x_14 for which if x_14 were a writer, then x_14 is a soldier, and that for all x_14, if x_14 were a soldier, then x_14 is a writer we can infer that there is at least one x_14 for which x_14 is a writer if and only if x_14 is a soldier. From the fact that there is at least one x_14 for which x_14 is a writer if and only if x_14 is a soldier we can infer that there is at least one x_14 for which if x_14 were a soldier, then x_14 is a writer. From the fact that for all x_14, x_14 is a soldier or x_14 is not a writer we can infer that for all x_14, if x_14 were a writer, then x_14 is a soldier. Finally, from the fact that there is at least one x_14 for which if x_14 were a soldier, then x_14 is a writer, and that for all x_14, if x_14 were a writer, then x_14 is a soldier we can infer that there is at least one x_14 for which x_14 is a soldier if and only if x_14 is a writer. Therefore, the answer is yes.