{ diff(x1, t) = (1*k10*(k1 + k2*x1*(1 - x1/k4)) + (-1)*k10*k3*x1*x2)/k10,
  diff(x2, t) = (1*k10*k5*x2*x3 + (-1)*k10*k6*x2)/k10,
  diff(x3, t) = (1*k10*k7*x3*(1 - x3/k8) + (-1)*k10*(k5*x2*x3 + k9*x3))/k10 }