Consider the following premises. Mary is not poor. For all x_1, if x_1 were rich, then x_1 is poor. For all x_1, x_1 is rich or x_1 is not poor. Can we infer the following from them? Mary is not rich.
 From the fact that for all x_1, x_1 is rich or x_1 is not poor we can infer that for all x_1, if x_1 were poor, then x_1 is rich. From the fact that for all x_1, if x_1 were rich, then x_1 is poor, and that for all x_1, if x_1 were poor, then x_1 is rich we can infer that for all x_1, x_1 is rich if and only if x_1 is poor. From the fact that for all x_1, x_1 is rich if and only if x_1 is poor we can infer that Mary is rich if and only if Mary is poor. Finally, from the fact that Mary is rich if and only if Mary is poor, and that Mary is not poor we can infer that Mary is not rich. Therefore, the answer is yes.