{ diff(x1, t) = 0,
  diff(x2, t) = ((-1)*x2*x10*k2 + (-1)*x2*k3 + (-1)*x2*x4*k6 + 1*x5*k7 + 1*x8*k11 + (-1)*x2*x6*k12 + 1*x7*k13)/k1,
  diff(x3, t) = (1*x2*x10*k2 + (-1)*x3*k4)/k1,
  diff(x4, t) = ((-1)*x2*x4*k6 + 1*x5*k7)/k1,
  diff(x5, t) = (1*x2*x4*k6 + (-1)*x5*k7)/k1,
  diff(x6, t) = ((-1)*x2*x6*k12 + 1*x7*k13)/k1,
  diff(x7, t) = (1*x2*x6*k12 + (-1)*x7*k13)/k1,
  diff(x8, t) = (1*x4*k8 + 1*x5*k9 + (-1)*x8*k10)/k1,
  diff(x9, t) = (1*x6*k14 + 1*x7*k15 + (-1)*x9*k16)/k1,
  diff(x10, t) = ((-1)*x2*x10*k2 + 1*x3*k4 + (-1)*x10*k5 + 1*x9*k17)/k1 }