{ diff(x1, t) = ((-1)*k36*k11*k27*x1/k36 + 1*k36*k16*x14/k36 + 1*k36*k17*x15/k36 + (-1)*k36*k19*k28*x1/k36 + 1*k36*k18*x16/k36 + (-1)*k36*k20*x11*x1/k36 + 1*k36*k24*x17/k36)/k36,
  diff(x2, t) = ((-1)*k36*k1*x2/k36 + (-1)*k36*k2*x2*x13/k36 + (-1)*k36*k3*x2*x1/k36 + 1*k36*k7*x12/k36)/k36,
  diff(x3, t) = ((-1)*k36*k6*x3*x7/k36 + 1*k36*k10*x8/k36 + (-1)*k36*k22*x3*x17/k36 + (-1)*k36*k23*x3*x18/k36 + 1*k36*k26*x9/k36)/k36,
  diff(x4, t) = ((-1)*k36*k4*x12*x4/k36 + 1*k36*k8*x5/k36)/k36,
  diff(x5, t) = (1*k36*k4*x12*x4/k36 + (-1)*k36*k8*x5/k36)/k36,
  diff(x6, t) = ((-1)*k36*k5*x5*x6/k36 + 1*k36*k9*x7/k36)/k36,
  diff(x7, t) = (1*k36*k5*x5*x6/k36 + (-1)*k36*k9*x7/k36)/k36,
  diff(x8, t) = (1*k36*k6*x3*x7/k36 + (-1)*k36*k10*x8/k36)/k36,
  diff(x9, t) = (1*k36*k22*x3*x17/k36 + 1*k36*k23*x3*x18/k36 + (-1)*k36*k26*x9/k36)/k36,
  diff(x10, t) = ((-1)*k36*k12*x10*x13/k36 + 1*k36*k14*x14/k36 + 1*k36*k16*x14/k36)/k36,
  diff(x11, t) = ((-1)*k36*k13*x11*x13/k36 + 1*k36*k15*x15/k36 + 1*k36*k17*x15/k36 + (-1)*k36*k20*x11*x1/k36 + 1*k36*k24*x17/k36 + (-1)*k36*k21*x11*x16/k36 + 1*k36*k25*x18/k36)/k36,
  diff(x12, t) = (1*k36*k1*x2/k36 + 1*k36*k2*x2*x13/k36 + 1*k36*k3*x2*x1/k36 + (-1)*k36*k7*x12/k36)/k36,
  diff(x13, t) = (1*k36*k11*k27*x1/k36 + (-1)*k36*k12*x10*x13/k36 + 1*k36*k14*x14/k36 + (-1)*k36*k13*x11*x13/k36 + 1*k36*k15*x15/k36)/k36,
  diff(x14, t) = (1*k36*k12*x10*x13/k36 + (-1)*k36*k14*x14/k36 + (-1)*k36*k16*x14/k36)/k36,
  diff(x15, t) = (1*k36*k13*x11*x13/k36 + (-1)*k36*k15*x15/k36 + (-1)*k36*k17*x15/k36)/k36,
  diff(x16, t) = (1*k36*k19*k28*x1/k36 + (-1)*k36*k18*x16/k36 + (-1)*k36*k21*x11*x16/k36 + 1*k36*k25*x18/k36)/k36,
  diff(x17, t) = (1*k36*k20*x11*x1/k36 + (-1)*k36*k24*x17/k36)/k36,
  diff(x18, t) = (1*k36*k21*x11*x16/k36 + (-1)*k36*k25*x18/k36)/k36,
  diff(x19, t) = 0/k36,
  diff(x20, t) = 0/k36 }