[ Eq(Derivative(x1, t), ((-1)*k19*k2*x1*x2/(1 + (x2/k18)**k17) + 1*k19*k1)/k19),
  Eq(Derivative(x2, t), ((-2)*k19*k2*x1*x2/(1 + (x2/k18)**k17) + 1*k19*(k4*k6*x4*x5*(k15 - x2) - k5*k7*x6*x2*(k16 - x5))/(k5*(k16 - x5) + k6*(k15 - x2)) + 1*k19*k8*x6*(k15 - x2) + (-1)*k19*k11*x2)/k19),
  Eq(Derivative(x3, t), (1*k19*k2*x1*x2/(1 + (x2/k18)**k17) + (-1)*k19*k3*x3)/k19),
  Eq(Derivative(x4, t), (2*k19*k3*x3 + (-1)*k19*(k4*k6*x4*x5*(k15 - x2) - k5*k7*x6*x2*(k16 - x5))/(k5*(k16 - x5) + k6*(k15 - x2)) + (-1)*k19*k12*x4*(k16 - x5))/k19),
  Eq(Derivative(x5, t), ((-1)*k19*(k4*k6*x4*x5*(k15 - x2) - k5*k7*x6*x2*(k16 - x5))/(k5*(k16 - x5) + k6*(k15 - x2)) + 1*k19*k12*x4*(k16 - x5) + 1*k19*k10*x8*(k16 - x5))/k19),
  Eq(Derivative(x6, t), (1*k19*(k4*k6*x4*x5*(k15 - x2) - k5*k7*x6*x2*(k16 - x5))/(k5*(k16 - x5) + k6*(k15 - x2)) + (-1)*k19*k8*x6*(k15 - x2))/k19),
  Eq(Derivative(x7, t), (1*k19*k8*x6*(k15 - x2) + (-1)*k19*k9*x7)/k19),
  Eq(Derivative(x8, t), (1*k19*k9*x7 + (-1)*k19*k14*(x8 - x9) + (-1)*k19*k10*x8*(k16 - x5))/k19),
  Eq(Derivative(x9, t), ((-1)*k19*k13*x9 + 1/10*k19*k14*(x8 - x9))/k19) ]