{{1, 0, 1/4, 0, 0, -1/2, -1/2, 0, 0, 0, -1/4, -1/4, 1/4}, 
 {0, 1, 1/4, 1/2, 0, -1/2, 0, -1/2, -1/2, -1/2, 3/4, 0, 1/4}, 
 {0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, -1}}
