Consider the following premises. If David were sad, then David is taking a plane. David is sad. If David takes a plane, then it is raining. Can we infer the following from them? It is not raining.
 From the fact that if David were sad, then David is taking a plane, and that if David takes a plane, then it is raining we can infer that if David were sad, then it is raining. Finally, from the fact that if David were sad, then it is raining, and that David is sad we can infer that it is raining, which contradicts that It is not raining. Therefore, the answer is no.