What are the different years in which there were cars produced that weighed less than 4000 and also cars that weighted more than 3000?
return cars  ;return weight of #1 ;return #1 where #2 is lower than 4000 ;return #1 where #2 is higher than 3000 ;return the  different years produced of both #3 and  #4
['select', 'project', 'comparative', 'comparative', 'intersection']