What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one z for which if z sleeps, then z is a server. For all z, if z were a writer, then z is a server. For all z, if z sleeps, then z is a writer. For all z, if z were a server, then z is sleeping.
For all z, if z were a writer, then z is sleeping. For all z, if z sleeps, then z is a server. For all z, if z were a server, then z is a writer. There is at least one z for which z will sleep if and only if z is a server. There is at least one z for which z is a server if and only if z will sleep.