{ diff(x1, t) = ((-1)*k2*(k3*x1*x2 - k4*x3) + 1*k2*(k15*x23 - k16*x1*x13))/k2,
  diff(x2, t) = ((-1)*k2*(k3*x1*x2 - k4*x3) + 1*k2*k5*x3 + (-1)*k2*(k6*x4*x2 - k7*x5) + 1*k2*k8*x5 + 1*k2*k22*x11 + (-1)*k2*(k23*x2*x13 - k24*x12) + (-1)*k2*(k37*x2*x20 - k38*x24))/k2,
  diff(x3, t) = (1*k2*(k3*x1*x2 - k4*x3) + (-1)*k2*k5*x3)/k2,
  diff(x4, t) = (1*k2*k5*x3 + (-1)*k2*(k6*x4*x2 - k7*x5) + 1*k2*k11*x21 + (-1)*k2*(k12*x4*x13 - k13*x22))/k2,
  diff(x5, t) = (1*k2*(k6*x4*x2 - k7*x5) + (-1)*k2*k8*x5)/k2,
  diff(x6, t) = (1*k2*k8*x5 + (-1)*k2*(k9*x6*x13 - k10*x21))/k2,
  diff(x7, t) = ((-1)*k2*(k17*x7*x8 - k18*x9) + 1*k2*(k29*x15 - k30*x7*x13) + 1*k2*(k43*x26 - k44*x7*x20))/k2,
  diff(x8, t) = ((-1)*k2*(k17*x7*x8 - k18*x9) + 1*k2*k19*x9 + (-1)*k2*(k20*x10*x8 - k21*x11) + 1*k2*k22*x11 + 1*k2*k33*x17 + (-1)*k2*(k34*x8*x20 - k35*x19))/k2,
  diff(x9, t) = (1*k2*(k17*x7*x8 - k18*x9) + (-1)*k2*k19*x9)/k2,
  diff(x10, t) = (1*k2*k19*x9 + (-1)*k2*(k20*x10*x8 - k21*x11) + 1*k2*k25*x12 + (-1)*k2*(k26*x10*x13 - k27*x14) + 1*k2*k39*x24 + (-1)*k2*(k40*x10*x20 - k41*x25))/k2,
  diff(x11, t) = (1*k2*(k20*x10*x8 - k21*x11) + (-1)*k2*k22*x11)/k2,
  diff(x12, t) = (1*k2*(k23*x2*x13 - k24*x12) + (-1)*k2*k25*x12)/k2,
  diff(x13, t) = ((-1)*k2*(k9*x6*x13 - k10*x21) + 1*k2*k11*x21 + (-1)*k2*(k12*x4*x13 - k13*x22) + 1*k2*(k15*x23 - k16*x1*x13) + (-1)*k2*(k23*x2*x13 - k24*x12) + 1*k2*k25*x12 + (-1)*k2*(k26*x10*x13 - k27*x14) + 1*k2*(k29*x15 - k30*x7*x13))/k2,
  diff(x14, t) = (1*k2*(k26*x10*x13 - k27*x14) + (-1)*k2*k28*x14)/k2,
  diff(x15, t) = (1*k2*k28*x14 + (-1)*k2*(k29*x15 - k30*x7*x13))/k2,
  diff(x16, t) = ((-1)*k2*(k31*x16*x18 - k32*x17) + 1*k2*(k45*x27 - k46*x16*x20))/k2,
  diff(x17, t) = (1*k2*(k31*x16*x18 - k32*x17) + (-1)*k2*k33*x17)/k2,
  diff(x18, t) = ((-1)*k2*(k31*x16*x18 - k32*x17) + 1*k2*k33*x17)/k2,
  diff(x19, t) = (1*k2*(k34*x8*x20 - k35*x19) + (-1)*k2*k36*x19)/k2,
  diff(x20, t) = ((-1)*k2*(k34*x8*x20 - k35*x19) + (-1)*k2*(k37*x2*x20 - k38*x24) + 1*k2*k39*x24 + (-1)*k2*(k40*x10*x20 - k41*x25) + 1*k2*(k43*x26 - k44*x7*x20) + 1*k2*(k45*x27 - k46*x16*x20))/k2,
  diff(x21, t) = (1*k2*(k9*x6*x13 - k10*x21) + (-1)*k2*k11*x21)/k2,
  diff(x22, t) = (1*k2*(k12*x4*x13 - k13*x22) + (-1)*k2*k14*x22)/k2,
  diff(x23, t) = (1*k2*k14*x22 + (-1)*k2*(k15*x23 - k16*x1*x13))/k2,
  diff(x24, t) = (1*k2*(k37*x2*x20 - k38*x24) + (-1)*k2*k39*x24)/k2,
  diff(x25, t) = (1*k2*(k40*x10*x20 - k41*x25) + (-1)*k2*k42*x25)/k2,
  diff(x26, t) = (1*k2*k42*x25 + (-1)*k2*(k43*x26 - k44*x7*x20))/k2,
  diff(x27, t) = (1*k2*k36*x19 + (-1)*k2*(k45*x27 - k46*x16*x20))/k2 }