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 were a scientist, then z is a sailor. For all z, z is a sailor. For all z, if z were a sailor, then z is a scientist. For all z, if z were a politician, then z is a scientist.
For all z, z is a scientist. There is at least one z for which if z were a politician, then z is a sailor. There is at least one z for which z is a scientist if and only if z is a sailor. There is at least one z for which z is a sailor if and only if z is a scientist.