Consider the following premises. For all z, z will drink water if and only if z will climb a mountain. Karen is climbing a mountain if and only if David is driving a car. David is driving a car if and only if it is sunny. For all z, z will not drink water. Can we infer the following from them? It is sunny.
 From the fact that for all z, z will drink water if and only if z will climb a mountain, and that for all z, z will not drink water we can infer that for all z, z will not climb a mountain. From the fact that for all z, z will not climb a mountain we can infer that Karen is not climbing a mountain. From the fact that Karen is climbing a mountain if and only if David is driving a car, and that Karen is not climbing a mountain we can infer that David is not driving a car. Finally, from the fact that David is driving a car if and only if it is sunny, and that David is not driving a car we can infer that it is not sunny, which contradicts that It is sunny. Therefore, the answer is no.