Consider the following premises. If it is cloudy, then Robert is a politician. Robert is not a politician. If David doesn't drink water, then Mary is a police officer. If David drinks water, then it is cloudy. Can we infer the following from them? If we can, name the inference rule being used: Mary is a police officer.
 From the fact that if David drinks water, then it is cloudy, and that if it is cloudy, then Robert is a politician we can infer that if David drinks water, then Robert is a politician via transitivity. From the fact that if David drinks water, then Robert is a politician, and that Robert is not a politician we can infer that David is not drinking water via modus tollens. Finally, from the fact that if David doesn't drink water, then Mary is a police officer, and that David is not drinking water we can infer that Mary is a police officer via modus ponens. Therefore, the answer is yes.