[ x[36] = x[10] + x[12] + x[17],
  x[37] = x[36]/8,
  x[38] = 8*(x[2] + x[5] + x[6]) + x[8] + x[9] + x[18] + x[19] + x[15] + x[16],
  x[39] = x[38]/8,
  1*k[49]*x[1] + 1*k[49]*x[2] = k[49]*k[57],
  1*k[49]*x[4] + 1*k[49]*x[5] = k[49]*k[58] ]