{{1, 0, 0, -1, -1, -1, 0, 0, 0, -2, -1/2, 0, 0, 1/2, 1/2, 0, -1/2, 0, 1}, 
 {0, 1, 0, -1, 0, 0, -1, 0, 0, -1, 0, -1/2, 0, 1/2, 0, 1/2, -1/2, 0, 1/2}, 
 {0, 0, 1, 0, 0, 0, 0, 0, 1, 3, 0, 0, -1/2, 0, 0, 0, -1/2, -1/2, -3/2}, 
 {0, 0, 0, 0, 0, 0, 0, 1, -3, -3, 0, 0, 1/2, 0, 0, 0, 1/2, 3/2, 5/2}}
