The Prenucleolus (Prescision=15 places): 

x1 = 400.0000000000000568 
x2 = 400.0000000000000000 
x3 = 200.0000000000000284 
x4 = 200.0000000000000853 

Excesses:

0.0000000000000000 ( )
0.0000000000000000 ( 1 2 3 4 )
-0.0000000000001137 ( 2 4 )
-0.0000000000001137 ( 1 3 )
-200.0000000000000000 ( 1 2 )
-200.0000000000000284 ( 3 )
-200.0000000000000853 ( 4 )
-200.0000000000001137 ( 2 3 4 )
-200.0000000000002274 ( 1 3 4 )
-400.0000000000000000 ( 2 )
-400.0000000000000000 ( 1 2 3 )
-400.0000000000000568 ( 1 )
-400.0000000000001137 ( 1 2 4 )
-400.0000000000001137 ( 3 4 )
-600.0000000000000000 ( 2 3 )
-600.0000000000001137 ( 1 4 )

Vector v:

0.0000000000000000 ( )
0.0000000000000000 ( 4 )
0.0000000000000000 ( 3 )
0.0000000000000000 ( 3 4 )
0.0000000000000000 ( 2 )
600.0000000000000000 ( 2 4 )
0.0000000000000000 ( 2 3 )
600.0000000000000000 ( 2 3 4 )
0.0000000000000000 ( 1 )
0.0000000000000000 ( 1 4 )
600.0000000000000000 ( 1 3 )
600.0000000000000000 ( 1 3 4 )
600.0000000000000000 ( 1 2 )
600.0000000000000000 ( 1 2 4 )
600.0000000000000000 ( 1 2 3 )
1200.0000000000000000 ( 1 2 3 4 )