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