{ x36 = x10 + x12 + x17,
  x37 = x36/8,
  x38 = 8*(x2 + x5 + x6) + x8 + x9 + x18 + x19 + x15 + x16,
  x39 = x38/8,
  1*k49*x1 + 1*k49*x2 = k49*k57,
  1*k49*x4 + 1*k49*x5 = k49*k58 }