What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z_3, z_3 is not a politician. For all z_3, z_3 is a nurse if and only if z_3 will read a book. There is at least one z_3 for which z_3 is a politician or z_3 is not a nurse.
There is at least one z_3 for which if z_3 were a nurse, then z_3 is a politician. For all z_3, if z_3 were a nurse, then z_3 is reading a book. For all z_3, if z_3 reads a book, then z_3 is a nurse.