{ x21 = x8 + x9,
  1*k36*x1 + 1*k36*x13 + 1*k36*x14 + 1*k36*x15 + 1*k36*x16 + 1*k36*x17 + 1*k36*x18 = k36*k37,
  1*k36*x2 + 1*k36*x12 = k36*k38,
  1*k36*x3 + 1*k36*x8 + 1*k36*x9 = k36*k39,
  1*k36*x4 + 1*k36*x5 = k36*k40,
  1*k36*x6 + 1*k36*x7 = k36*k41,
  1*k36*x10 + 1*k36*x14 = k36*k42,
  1*k36*x11 + 1*k36*x15 + 1*k36*x17 + 1*k36*x18 = k36*k43 }