query: SELECT rank FROM captain EXCEPT SELECT rank FROM captain WHERE CLASS  =  'Third-rate ship of the line'
question: What are the ranks of captains that have no captain that are in the Third-rate ship of the line class?
query_toks: SELECT rank FROM captain EXCEPT SELECT rank FROM captain WHERE CLASS = 'Third-rate ship of the line '
query_toks_no_value: select rank from captain except select rank from captain where class = value
question_toks: What are the ranks of captains that have no captain that are in the Third-rate ship of the line class?