{ diff(x1, t) = ((-1)*k61*k4*x1*x32 + 1*k61*k6*x3)/k61,
  diff(x2, t) = (1*k61*k4*x1*x32 + (-1)*k61*k5*x2)/k61,
  diff(x3, t) = (1*k61*k5*x2 + (-1)*k61*k6*x3)/k61,
  diff(x4, t) = ((-1)*k61*k1*x4*x33 + (-1)*k61*k7*x4*x2 + (-1)*k61*k9*x4*x23 + 1*k61*k10*x6)/k61,
  diff(x5, t) = (1*k61*k1*x4*x33 + 1*k61*k7*x4*x2 + (-1)*k61*k8*x5*x23)/k61,
  diff(x6, t) = (1*k61*k8*x5*x23 + 1*k61*k9*x4*x23 + (-1)*k61*k10*x6)/k61,
  diff(x7, t) = ((-1)*k61*k2*x7*x33 + (-1)*k61*k11*x7*x5 + 1*k61*k12*x8)/k61,
  diff(x8, t) = (1*k61*k2*x7*x33 + 1*k61*k11*x7*x5 + (-1)*k61*k12*x8)/k61,
  diff(x9, t) = ((-1)*k61*k15*x9*x31 + (-1)*k61*k13*x9*x19 + 1*k61*k17*x10 + 1*k61*k19*x11)/k61,
  diff(x10, t) = (1*k61*k15*x9*x31 + (-1)*k61*k14*x10*x19 + (-1)*k61*k17*x10 + 1*k61*k20*x12)/k61,
  diff(x11, t) = (1*k61*k13*x9*x19 + (-1)*k61*k16*x11*x31 + (-1)*k61*k19*x11 + 1*k61*k18*x12)/k61,
  diff(x12, t) = (1*k61*k16*x11*x31 + 1*k61*k14*x10*x19 + (-1)*k61*k18*x12 + (-1)*k61*k20*x12)/k61,
  diff(x13, t) = ((-1)*k61*k21*x13*x8 + (-1)*k61*k22*x13*(x10 + x12) + 1*k61*k23*x15 + 1*k61*k24*x14)/k61,
  diff(x14, t) = (1*k61*k22*x13*(x10 + x12) + (-1)*k61*k24*x14)/k61,
  diff(x15, t) = (1*k61*k21*x13*x8 + (-1)*k61*k23*x15)/k61,
  diff(x16, t) = (1*k61*k25*x17*(x13 + x15) + (-1)*k61*k26*x16*x33)/k61,
  diff(x17, t) = ((-1)*k61*k25*x17*(x13 + x15) + 1*k61*k26*x16*x33)/k61,
  diff(x18, t) = ((-1)*k61*k3*x18*x33 + (-1)*k61*k28*x18*x29 + 1*k61*k27*x19)/k61,
  diff(x19, t) = (1*k61*k3*x18*x33 + 1*k61*k28*x18*x29 + (-1)*k61*k27*x19)/k61,
  diff(x20, t) = ((-1)*k61*k29*x20*x31 + (-1)*k61*k31*x20*x17 + 1*k61*k33*x21 + 1*k61*k35*x22)/k61,
  diff(x21, t) = (1*k61*k29*x20*x31 + (-1)*k61*k32*x21*x17 + (-1)*k61*k33*x21 + 1*k61*k36*x23)/k61,
  diff(x22, t) = (1*k61*k31*x20*x17 + (-1)*k61*k30*x22*x31 + (-1)*k61*k35*x22 + 1*k61*k34*x23)/k61,
  diff(x23, t) = (1*k61*k30*x22*x31 + 1*k61*k32*x21*x17 + (-1)*k61*k34*x23 + (-1)*k61*k36*x23)/k61,
  diff(x24, t) = ((-1)*k61*k37*x24*x17 + (-1)*k61*k39*x24*(x10 + x12) + 1*k61*k41*x26 + 1*k61*k43*x25)/k61,
  diff(x25, t) = (1*k61*k39*x24*(x10 + x12) + (-1)*k61*k38*x25*x17 + (-1)*k61*k43*x25 + 1*k61*k42*x27)/k61,
  diff(x26, t) = (1*k61*k37*x24*x17 + (-1)*k61*k40*x26*(x10 + x12) + (-1)*k61*k41*x26 + 1*k61*k44*x27)/k61,
  diff(x27, t) = (1*k61*k40*x26*(x10 + x12) + 1*k61*k38*x25*x17 + (-1)*k61*k42*x27 + (-1)*k61*k44*x27)/k61,
  diff(x28, t) = (1*k61*k47*x29 + (-1)*k61*k48*x28*x2)/k61,
  diff(x29, t) = ((-1)*k61*k47*x29 + 1*k61*k48*x28*x2)/k61,
  diff(x30, t) = (1*k61*k45*x31 + (-1)*k61*k46*x30*x5)/k61,
  diff(x31, t) = ((-1)*k61*k45*x31 + 1*k61*k46*x30*x5)/k61 }