Consider the following premises. William is not writing a letter. For all x_14, x_14 is excited if and only if x_14 will write a letter. If it snows, then James is happy. If William were not excited, then James is happy. Can we infer the following from them? James is not happy.
 From the fact that for all x_14, x_14 is excited if and only if x_14 will write a letter we can infer that William is excited if and only if William is writing a letter. From the fact that William is excited if and only if William is writing a letter, and that William is not writing a letter we can infer that William is not excited. From the fact that William is not excited we can infer that William is not excited or it is snowing. Finally, from the fact that if William were not excited, then James is happy, that if it snows, then James is happy, and that William is not excited or it is snowing we can infer that James is happy, which contradicts that James is not happy. Therefore, the answer is no.