What are the ranks of captains that are both in the Cutter and Armed schooner classes?
return captains ;return classes of  #1 ;return #1 where #2 is  Cutter ;return #1 where #2 is  Armed schooner ;return #1 of  both #3 and  #4 ;return ranks of  #5
['select', 'project', 'comparative', 'comparative', 'intersection', 'project']