Consider the following premises. Barbara is not playing a game or Susan is a nurse. Barbara is playing a game or Charles is a server. If Charles were a server, then Jessica is sad. Jessica is sad if and only if Susan is a nurse. Can we infer the following from them? Jessica is not sad.
 From the fact that Jessica is sad if and only if Susan is a nurse we can infer that if Susan were a nurse, then Jessica is sad. From the fact that Barbara is playing a game or Charles is a server, and that Barbara is not playing a game or Susan is a nurse we can infer that Charles is a server or Susan is a nurse. Finally, from the fact that if Charles were a server, then Jessica is sad, that if Susan were a nurse, then Jessica is sad, and that Charles is a server or Susan is a nurse we can infer that Jessica is sad, which contradicts that Jessica is not sad. Therefore, the answer is no.