on the earliest flight from san francisco to atlanta on delta is a meal being served 
return flights ;return #1 on delta ;return #2 from  san francisco ;return #3 to atlanta ;return when  are #4 ;return #4 where #5 is the  lowest ;return if #6 has a meal
['select', 'filter', 'filter', 'filter', 'project', 'comparative', 'boolean']