{ diff(x1, t) = ((-1)*(k13*x1*(x21*k51 - x4*k51 - x5)*k51 - k14*x4*k51) + (-1)*(k1*x1*k51 - k2*x9*k52) + 1*k21*x7*k51)/k51,
  diff(x2, t) = (1*k15*x4*k51 + (-1)*(k13*x2*(x21*k51 - x5*k51 - x4)*k51 - k14*x5*k51) + (-1)*(k3*x2*k51 - k4*x10*k52) + 1*k18*x8*k51 + (-1)*(k19*x2*x6/(47/50)*k51 - k20*x7)*k51)/k51,
  diff(x3, t) = (1*k15*x5*k51 + (-1)*(k5*x3*k51 - k6*x11*k52) + (-1)*(k16*x3*x6/(47/50)*k51 - k17*x8)*k51)/k51,
  diff(x4, t) = (1*(k13*x1*(x21*k51 - x4*k51 - x5)*k51 - k14*x4*k51) + (-1)*k15*x4*k51)/k51,
  diff(x5, t) = (1*(k13*x2*(x21*k51 - x5*k51 - x4)*k51 - k14*x5*k51) + (-1)*k15*x5*k51)/k51,
  diff(x6, t) = ((-1)*(k16*x3*x6/(47/50)*k51 - k17*x8)*k51 + 1*k18*x8*k51 + (-1)*(k19*x2*x6/(47/50)*k51 - k20*x7)*k51 + 1*k21*x7*k51)/k51,
  diff(x7, t) = (1*(k19*x2*x6/(47/50)*k51 - k20*x7)*k51 + (-1)*k21*x7*k51)/k51,
  diff(x8, t) = (1*(k16*x3*x6/(47/50)*k51 - k17*x8)*k51 + (-1)*k18*x8*k51)/k51,
  diff(x9, t) = (1*(k1*x1*k51 - k2*x9*k52) + 1*k32*x12*k52 + (-1)*(k7*x9*x14/(11/50)*k52 - k8*x15)*k52)/k52,
  diff(x10, t) = (1*(k3*x2*k51 - k4*x10*k52) + 1*k29*x13*k52 + (-1)*(k30*x10*x19/(11/50)*k52 - k31*x12)*k52 + (-1)*(k9*x10*x14/(11/50)*k52 - k10*x16)*k52)/k52,
  diff(x11, t) = (1*(k5*x3*k51 - k6*x11*k52) + (-1)*(k27*x11*x19/(11/50)*k52 - k28*x13)*k52 + (-1)*(k11*x11*x14/(11/50)*k52 - k12*x17)*k52)/k52,
  diff(x12, t) = (1*(k30*x10*x19/(11/50)*k52 - k31*x12)*k52 + (-1)*k32*x12*k52)/k52,
  diff(x13, t) = (1*(k27*x11*x19/(11/50)*k52 - k28*x13)*k52 + (-1)*k29*x13*k52)/k52,
  diff(x14, t) = ((-1)*(k7*x9*x14/(11/50)*k52 - k8*x15)*k52 + (-1)*(k9*x10*x14/(11/50)*k52 - k10*x16)*k52 + (-1)*(k11*x11*x14/(11/50)*k52 - k12*x17)*k52)/k52,
  diff(x15, t) = 1*(k7*x9*x14/(11/50)*k52 - k8*x15)*k52/k52,
  diff(x16, t) = 1*(k9*x10*x14/(11/50)*k52 - k10*x16)*k52/k52,
  diff(x17, t) = 1*(k11*x11*x14/(11/50)*k52 - k12*x17)*k52/k52,
  diff(x18, t) = (1*k37*(1 + k38*x11^2/(x11^2*k52 + k39^2))*693/1000/k40 + (-1)*x18*693/1000/k40*k52)/k52,
  diff(x19, t) = ((-1)*(k27*x11*x19/(11/50)*k52 - k28*x13)*k52 + 1*k29*x13*k52 + (-1)*(k30*x10*x19/(11/50)*k52 - k31*x12)*k52 + 1*k32*x12*k52 + 1*k41*x18/(11/50)*693/1000/k42*k52 + (-1)*x19*693/1000/k42*k52)/k52 }