{{b[1], b[2], -1/2*b[1] + b[2]/2, -1/2*b[1] + b[2]/2}, {-b[1], b[2]/2, b[2]/2, -b[1] + b[2]}, {-1/2*b[2], -1/2*b[2], -b[1] + b[2]/2, -b[1] + (3*b[2])/2}, {-b[2], b[1] - b[2]/2, -1/2*b[1] + b[2]/2, -1/2*b[1] + b[2]}, {b[1]/2 - b[2]/2, b[1]/2 - b[2]/2, -1/2*b[1] + (3*b[2])/2, b[1]/2 + b[2]/2}, {b[1]/2 - b[2]/2, b[1]/2 - (3*b[2])/2, b[1]/2, b[1]/2}, {b[1] - b[2], -1/2*b[1] - b[2]/2, -1/2*b[1] + b[2], b[2]/2}, {b[1]/2 - b[2], -1/2*b[1], b[1]/2 - b[2], b[1]/2}, {b[1] - (3*b[2])/2, -1/2*b[1], -1/2*b[2], -1/2*b[1]}}