Consider the following premises. William is drinking water if and only if Richard is writing a letter. It is windy. If William drinks water, then it is not windy. If William drinks water, then Richard is writing a letter. Can we infer the following from them? Richard is writing a letter.
 From the fact that William is drinking water if and only if Richard is writing a letter we can infer that if Richard writes a letter, then William is drinking water. From the fact that if Richard writes a letter, then William is drinking water, and that if William drinks water, then Richard is writing a letter we can infer that Richard is writing a letter if and only if William is drinking water. From the fact that if William drinks water, then it is not windy, and that it is windy we can infer that William is not drinking water. Finally, from the fact that Richard is writing a letter if and only if William is drinking water, and that William is not drinking water we can infer that Richard is not writing a letter, which contradicts that Richard is writing a letter. Therefore, the answer is no.