{ diff(x1, t) = (1*k26*k1 + 1*k26*k2*x3^k3/(k4^k3 + x3^k3) + 1*k26*k5*x4 + (-1)*k26*k6*x1)/k26,
  diff(x2, t) = (1*k26*k7 + 1*k26*k8*x1^k3/(k9^k3 + x1^k3) + 1*k26*k10*x5 + (-1)*k26*k11*x2)/k26,
  diff(x3, t) = (1*k26*k12 + 1*k26*k13*x2^k3/(k14^k3 + x2^k3) + 1*k26*k15*x6 + (-1)*k26*k16*x3)/k26,
  diff(x4, t) = (1*k26*k17*x1^k3/(k18^k3 + x1^k3 + x5^k3) + (-1)*k26*k19*x4)/k26,
  diff(x5, t) = (1*k26*k20*x2^k3/(k21^k3 + x2^k3 + x6^k3) + (-1)*k26*k22*x5)/k26,
  diff(x6, t) = (1*k26*k23*x3^k3/(k24^k3 + x3^k3 + x4^k3) + (-1)*k26*k25*x6)/k26 }