The Prenucleolus: 

x1 = 600
x2 = 600
x3 = 1e-06
x4 = 1e-06

Excesses:

0 ()
-6.82121e-11 (2 )
-6.85532e-11 (1 4 )
-6.85532e-11 (1 3 )
-1.36879e-10 (1 2 3 )
-1e-06 (3 )
-1e-06 (4 )
-1.00007e-06 (2 3 )
-1.00014e-06 (1 2 3 4 )
-2e-06 (3 4 )
-600 (1 )
-600 (1 2 )
-600 (1 2 4 )
-600 (2 4 )
-600 (1 3 4 )
-600 (2 3 4 )