Consider the following premises. If Thomas were rich, then Elisabeth is sad. If Thomas writes a letter, then Elisabeth is sad. If Elisabeth were sad, then Thomas is writing a letter. Robert is not driving a car. Robert is driving a car if and only if Thomas is writing a letter. Can we infer the following from them? Thomas is rich.
 From the fact that if Elisabeth were sad, then Thomas is writing a letter, and that if Thomas writes a letter, then Elisabeth is sad we can infer that Elisabeth is sad if and only if Thomas is writing a letter. From the fact that Robert is driving a car if and only if Thomas is writing a letter, and that Robert is not driving a car we can infer that Thomas is not writing a letter. From the fact that Elisabeth is sad if and only if Thomas is writing a letter, and that Thomas is not writing a letter we can infer that Elisabeth is not sad. Finally, from the fact that if Thomas were rich, then Elisabeth is sad, and that Elisabeth is not sad we can infer that Thomas is not rich, which contradicts that Thomas is rich. Therefore, the answer is no.