Did Bremen become a Free imperial city before or after the end of the Thirty Years' War?
return Bremen become a Free imperial city ;return the  end of the Thirty Years War ;return when  was  #1 ;return when  was  #2 ;return is #3 lower than #4 ;return is #3 higher than #4 ;return which is true of #5 ,  #6
['select', 'select', 'project', 'project', 'boolean', 'boolean', 'comparison']