Consider the following premises. It is snowing. If it snows, then David is curious. If David were curious, then it is snowing. Can we infer the following from them? David is not curious.
 From the fact that if it snows, then David is curious, and that if David were curious, then it is snowing we can infer that it is snowing if and only if David is curious. From the fact that it is snowing if and only if David is curious we can infer that if it snows, then David is curious. Finally, from the fact that if it snows, then David is curious, and that it is snowing we can infer that David is curious, which contradicts that David is not curious. Therefore, the answer is no.