{ diff(x1, t) = (1*k2*(k3*k10*x2 - x1*x3)/(1 + k10 + x2 + x1 + x3 + k10*x2 + x1*x3) + (-1)*k6*(k7*x1 - k11)/(1 + x1 + k11) + (-1)*k8*(k9*x1 - k12)/(1 + x1 + k12))/k1,
  diff(x2, t) = ((-1)*k2*(k3*k10*x2 - x1*x3)/(1 + k10 + x2 + x1 + x3 + k10*x2 + x1*x3) + 1*k4*(k5*k13*x3 - k14*x2)/(1 + x3 + x2 + k13 + k14 + x3*k13 + x2*k14))/k1,
  diff(x3, t) = (1*k2*(k3*k10*x2 - x1*x3)/(1 + k10 + x2 + x1 + x3 + k10*x2 + x1*x3) + (-1)*k4*(k5*k13*x3 - k14*x2)/(1 + x3 + x2 + k13 + k14 + x3*k13 + x2*k14))/k1,
  diff(x4, t) = 0,
  diff(x5, t) = 0,
  diff(x6, t) = 0,
  diff(x7, t) = 0,
  diff(x8, t) = 0 }