How many more points did the Pittsburgh Steelers score than the Washington Redskins in 2008?
return the  Pittsburgh Steelers ;return points of #1 ;return #2 in  2008 ;return sum of #3 ;return the  Washington Redskins ;return points of #5 ;return #6 in  2008 ;return sum of #7 ;return difference of #4 and  #8
['select', 'project', 'filter', 'aggregate', 'select', 'project', 'filter', 'aggregate', 'arithmetic']