how to load this relation

[prasenjit mukherjee]

I am tryign this load statement to load the following data : r = load
'tmp.dat' AS (f1:int, f2:int, B: bag { T: tuple (g1:int, g2:int) });

1,2,{(3,4),(5,6)}
1,2,{(3,4),(5,6),(10,12)}
7,8,{(3,4)}

But it is not working. Any help ?

-Thanks,
Prasen