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