If there is a bowl of mashed potatoes with melted butter on top
return bowl of mashed potatoes ;return butter ;return #2 that is melted ;return top of #1 ;return #3 that is on #4 ;return #1 that has #5 ;return number of  #6 ;return if  #7 is at least one
['select', 'select', 'filter', 'project', 'filter', 'filter', 'aggregate', 'boolean']