Consider the following premises. Jennifer is a server if and only if David is playing tennis. David is playing tennis if and only if Richard is happy. It is late. If Jennifer were a server, then it is not late. Can we infer the following from them? Richard is happy.
 From the fact that if Jennifer were a server, then it is not late, and that it is late we can infer that Jennifer is not a server. From the fact that Jennifer is a server if and only if David is playing tennis, and that Jennifer is not a server we can infer that David is not playing tennis. From the fact that David is playing tennis if and only if Richard is happy we can infer that if Richard were happy, then David is playing tennis. Finally, from the fact that if Richard were happy, then David is playing tennis, and that David is not playing tennis we can infer that Richard is not happy, which contradicts that Richard is happy. Therefore, the answer is no.