Find the name of the ships that are steered by both a captain with Midshipman rank and a captain with Lieutenant rank.
return ships ;return captains that steered #1 ;return ranks of #2 ;return #1 where #3 is Midshipman ;return #1 where #3 is Lieutenant ;return #1 of both #4 and  #5 ;return name of #6
['select', 'project', 'project', 'comparative', 'comparative', 'intersection', 'project']