{ diff(x1, t) = (1*k1*k22 + (-1)*k2*x1*x9 + 1*k3*x2)/k18,
  diff(x2, t) = (1*k2*x1*x9 + (-1)*k3*x2 + (-1)*k4*x2*x6 + 1*k5*x12 + 1*k10*x13*x7 + (-2)*k14*x2*(x2 - 1)*1/2 + (-1)*k14*x2*x37 + (-1)*k15*x13*x2 + (-1)*k15*x14*x2 + (-1)*k15*x15*x2 + (-1)*k15*x16*x2 + (-1)*k15*x17*x2 + (-1)*k15*x18*x2 + (-1)*k15*x19*x2 + (-1)*k15*x20*x2)/k18,
  diff(x3, t) = ((-1)*k6*x4*x3*k19/(5000 + k19) + 1*k10*x20*x7 + 1*k10*x19*x7 + 1*k10*x18*x7 + 1*k10*x17*x7 + 1*k10*x16*x7 + 1*k10*x15*x7 + 1*k10*x14*x7 + 1*k10*x13*x7 + 1*k12*x25*x7 + 1*k12*x24*x7 + 1*k12*x23*x7 + 1*k12*x22*x7 + 1*k12*x21*x7 + 4*k13*x21*k19/(5000 + k19) + 5*k13*x22*k19/(5000 + k19) + 6*k13*x23*k19/(5000 + k19) + 7*k13*x24*k19/(5000 + k19) + 8*k13*x25*k19/(5000 + k19))/k18,
  diff(x4, t) = ((-1)*k6*x4*x3*k19/(5000 + k19) + 1*k7*x5*x10)/k18,
  diff(x5, t) = ((-1)*k7*x5*x10 + 1*k8*x11*x12 + 1*k9*x13*x11 + 1*k9*x14*x11 + 1*k9*x15*x11 + 1*k9*x16*x11 + 1*k9*x17*x11 + 1*k9*x18*x11 + 1*k9*x19*x11)/k18,
  diff(x6, t) = ((-1)*k4*x2*x6 + 1*k5*x12 + 1*k8*x11*x12)/k18,
  diff(x7, t) = 0/k18,
  diff(x8, t) = ((-1)*k11*x16*x8 + (-1)*k11*x17*x8 + (-1)*k11*x18*x8 + (-1)*k11*x19*x8 + (-1)*k11*x20*x8 + 1*k12*x21*x7 + 1*k13*x21*k19/(5000 + k19) + 1*k13*x22*k19/(5000 + k19) + 1*k13*x23*k19/(5000 + k19) + 1*k13*x24*k19/(5000 + k19) + 1*k13*x25*k19/(5000 + k19) + (-1)*k17*x37*x8)/k18,
  diff(x9, t) = 0/k18,
  diff(x10, t) = (1*k6*x4*x3*k19/(5000 + k19) + (-1)*k7*x5*x10)/k18,
  diff(x11, t) = (1*k7*x5*x10 + (-1)*k8*x11*x12 + (-1)*k9*x13*x11 + (-1)*k9*x14*x11 + (-1)*k9*x15*x11 + (-1)*k9*x16*x11 + (-1)*k9*x17*x11 + (-1)*k9*x18*x11 + (-1)*k9*x19*x11)/k18,
  diff(x12, t) = (1*k4*x2*x6 + (-1)*k5*x12 + (-1)*k8*x11*x12)/k18,
  diff(x13, t) = (1*k8*x11*x12 + (-1)*k9*x13*x11 + 1*k10*x14*x7 + (-1)*k10*x13*x7 + (-2)*k15*x13*(x13 - 1)*1/2 + (-1)*k15*x13*x2 + (-1)*k15*x13*x37 + (-1)*k15*x13*x14 + (-1)*k15*x13*x15 + (-1)*k15*x13*x16 + (-1)*k15*x13*x17 + (-1)*k15*x13*x18 + (-1)*k15*x13*x19 + (-1)*k15*x13*x20)/k18,
  diff(x14, t) = (1*k9*x13*x11 + (-1)*k9*x14*x11 + 1*k10*x15*x7 + (-1)*k10*x14*x7 + (-2)*k15*x14*(x14 - 1)*1/2 + (-1)*k15*x14*x2 + (-1)*k15*x14*x37 + (-1)*k15*x13*x14 + (-1)*k15*x14*x15 + (-1)*k15*x14*x16 + (-1)*k15*x14*x17 + (-1)*k15*x14*x18 + (-1)*k15*x14*x19 + (-1)*k15*x14*x20)/k18,
  diff(x15, t) = (1*k9*x14*x11 + (-1)*k9*x15*x11 + 1*k10*x16*x7 + (-1)*k10*x15*x7 + 1*k12*x21*x7 + (-2)*k15*x15*(x15 - 1)*1/2 + (-1)*k15*x15*x2 + (-1)*k15*x15*x37 + (-1)*k15*x13*x15 + (-1)*k15*x14*x15 + (-1)*k15*x15*x16 + (-1)*k15*x15*x17 + (-1)*k15*x15*x18 + (-1)*k15*x15*x19 + (-1)*k15*x15*x20)/k18,
  diff(x16, t) = (1*k9*x15*x11 + (-1)*k9*x16*x11 + 1*k10*x17*x7 + (-1)*k10*x16*x7 + (-1)*k11*x16*x8 + (-2)*k15*x16*(x16 - 1)*1/2 + (-1)*k15*x16*x2 + (-1)*k15*x16*x37 + (-1)*k15*x13*x16 + (-1)*k15*x14*x16 + (-1)*k15*x15*x16 + (-1)*k15*x16*x17 + (-1)*k15*x16*x18 + (-1)*k15*x16*x19 + (-1)*k15*x16*x20)/k18,
  diff(x17, t) = (1*k9*x16*x11 + (-1)*k9*x17*x11 + 1*k10*x18*x7 + (-1)*k10*x17*x7 + (-1)*k11*x17*x8 + (-2)*k15*x17*(x17 - 1)*1/2 + (-1)*k15*x17*x2 + (-1)*k15*x17*x37 + (-1)*k15*x13*x17 + (-1)*k15*x14*x17 + (-1)*k15*x15*x17 + (-1)*k15*x16*x17 + (-1)*k15*x17*x18 + (-1)*k15*x17*x19 + (-1)*k15*x17*x20)/k18,
  diff(x18, t) = (1*k9*x17*x11 + (-1)*k9*x18*x11 + 1*k10*x19*x7 + (-1)*k10*x18*x7 + (-1)*k11*x18*x8 + (-2)*k15*x18*(x18 - 1)*1/2 + (-1)*k15*x18*x2 + (-1)*k15*x18*x37 + (-1)*k15*x13*x18 + (-1)*k15*x14*x18 + (-1)*k15*x15*x18 + (-1)*k15*x16*x18 + (-1)*k15*x17*x18 + (-1)*k15*x18*x19 + (-1)*k15*x18*x20)/k18,
  diff(x19, t) = (1*k9*x18*x11 + (-1)*k9*x19*x11 + 1*k10*x20*x7 + (-1)*k10*x19*x7 + (-1)*k11*x19*x8 + (-2)*k15*x19*(x19 - 1)*1/2 + (-1)*k15*x19*x2 + (-1)*k15*x19*x37 + (-1)*k15*x13*x19 + (-1)*k15*x14*x19 + (-1)*k15*x15*x19 + (-1)*k15*x16*x19 + (-1)*k15*x17*x19 + (-1)*k15*x18*x19 + (-1)*k15*x19*x20)/k18,
  diff(x20, t) = (1*k9*x19*x11 + (-1)*k10*x20*x7 + (-1)*k11*x20*x8 + (-2)*k15*x20*(x20 - 1)*1/2 + (-1)*k15*x20*x2 + (-1)*k15*x20*x37 + (-1)*k15*x13*x20 + (-1)*k15*x14*x20 + (-1)*k15*x15*x20 + (-1)*k15*x16*x20 + (-1)*k15*x17*x20 + (-1)*k15*x18*x20 + (-1)*k15*x19*x20)/k18,
  diff(x21, t) = (1*k11*x16*x8 + 1*k12*x22*x7 + (-1)*k12*x21*x7 + (-1)*k13*x21*k19/(5000 + k19))/k18,
  diff(x22, t) = (1*k11*x17*x8 + 1*k12*x23*x7 + (-1)*k12*x22*x7 + (-1)*k13*x22*k19/(5000 + k19))/k18,
  diff(x23, t) = (1*k11*x18*x8 + 1*k12*x24*x7 + (-1)*k12*x23*x7 + (-1)*k13*x23*k19/(5000 + k19))/k18,
  diff(x24, t) = (1*k11*x19*x8 + 1*k12*x25*x7 + (-1)*k12*x24*x7 + (-1)*k13*x24*k19/(5000 + k19))/k18,
  diff(x25, t) = (1*k11*x20*x8 + (-1)*k12*x25*x7 + (-1)*k13*x25*k19/(5000 + k19))/k18,
  diff(x26, t) = 0,
  diff(x27, t) = 0,
  diff(x28, t) = 0,
  diff(x29, t) = 0,
  diff(x30, t) = 1*k13*x21*k19/(5000 + k19)/k18,
  diff(x31, t) = 1*k13*x22*k19/(5000 + k19)/k18,
  diff(x32, t) = 1*k13*x23*k19/(5000 + k19)/k18,
  diff(x33, t) = 1*k13*x24*k19/(5000 + k19)/k18,
  diff(x34, t) = 1*k13*x25*k19/(5000 + k19)/k18,
  diff(x35, t) = 1*k2*x1*x9/k18,
  diff(x36, t) = 1*k3*x2/k18,
  diff(x37, t) = (1*k14*x2*(x2 - 1)*1/2 + 1*k14*x2*x37 + 1*k15*x13*(x13 - 1)*1/2 + 1*k15*x14*(x14 - 1)*1/2 + 1*k15*x15*(x15 - 1)*1/2 + 1*k15*x16*(x16 - 1)*1/2 + 1*k15*x17*(x17 - 1)*1/2 + 1*k15*x18*(x18 - 1)*1/2 + 1*k15*x19*(x19 - 1)*1/2 + 1*k15*x20*(x20 - 1)*1/2 + 1*k15*x13*x2 + 1*k15*x14*x2 + 1*k15*x15*x2 + 1*k15*x16*x2 + 1*k15*x17*x2 + 1*k15*x18*x2 + 1*k15*x19*x2 + 1*k15*x20*x2 + 1*k15*x13*x37 + 1*k15*x14*x37 + 1*k15*x15*x37 + 1*k15*x16*x37 + 1*k15*x17*x37 + 1*k15*x18*x37 + 1*k15*x19*x37 + 1*k15*x20*x37 + 1*k15*x13*x14 + 1*k15*x13*x15 + 1*k15*x13*x16 + 1*k15*x13*x17 + 1*k15*x13*x18 + 1*k15*x13*x19 + 1*k15*x13*x20 + 1*k15*x14*x15 + 1*k15*x14*x16 + 1*k15*x14*x17 + 1*k15*x14*x18 + 1*k15*x14*x19 + 1*k15*x14*x20 + 1*k15*x15*x16 + 1*k15*x15*x17 + 1*k15*x15*x18 + 1*k15*x15*x19 + 1*k15*x15*x20 + 1*k15*x16*x17 + 1*k15*x16*x18 + 1*k15*x16*x19 + 1*k15*x16*x20 + 1*k15*x17*x18 + 1*k15*x17*x19 + 1*k15*x17*x20 + 1*k15*x18*x19 + 1*k15*x18*x20 + 1*k15*x19*x20 + (-1)*k16*x37 + (-1)*k17*x37*x8)/k18,
  diff(x38, t) = 1*k16*x37/k18,
  diff(x39, t) = 1*k17*x37*x8/k18 }