{ diff(x1, t) = (1*k45*k1*x1*(1 - k2*x1) + (-1)*k45*k3*x2*x1 + (-1)*k45*k42*(x3/x1)^k43/(k44 + (x3/x1)^k43)*x1 + (-1)*k45*k4*(1 - exp((-1)*k5*x5))*x1)/k45,
  diff(x2, t) = ((-1)*k45*k8*x2*x1 + 1*k45*k9*x2*x6/(k10 + x6) + (-1)*k45*k11*(1 - exp((-1)*k12*x5))*x2 + 1*k45*k7*(k6*x4 - x2))/k45,
  diff(x3, t) = ((-1)*k45*k33*k13*x3/(k33 + x6) + (-1)*k45*k15*x3*x1 + 1*k45*k16*x2*x1 + 1*k45*k17*x4*x1 + (-1)*k45*k20*x3^2*x4*x6/(k21 + x6) + 1*k45*k22*x1*x3/(k23 + x1) + (-1)*k45*k24*(1 - exp((-1)*k25*x5))*x3 + 1*k45*k18*x3*x6/(k19 + x6) + 1*k45*k41)/k45,
  diff(x4, t) = (1*k45*k27*(k26 - x4) + (-1)*k45*k28*(1 - exp((-1)*k29*x5))*x4)/k45,
  diff(x5, t) = ((-1)*k45*k30*x5 + 1*k45*k39)/k45,
  diff(x6, t) = ((-1)*k45*k31*x6 + 1*k45*k33*x4 + 1*k45*k32*x3*x6/(k34 + x6) + 1*k45*k40)/k45 }