show me the cheapest one way flights from pittsburgh to dallas leaving pittsburgh between noon and 2pm 
return flights ;return #1 from pittsburgh  ;return #2 to  dallas ;return #3 that  are leaving pittsburgh  between noon and 2pm ;return #4 that  are one way ;return price of #5 ;return #5 where #6 is  the  lowest
['select', 'filter', 'filter', 'filter', 'filter', 'project', 'comparative']