[ Eq(Derivative(x1, t), 0),
  Eq(Derivative(x2, t), 0),
  Eq(Derivative(x3, t), ((-1)*k12*(k1*x3*x18 - k4*x17) + (-1)*k12*(k1*x29*x3 - k4*x33))/k12),
  Eq(Derivative(x4, t), (1*k12*k18*k64*x3 + (-1)*k12*k19*x4 + 1*k12*k9*k64*x17 + 1*k12*k9*k64*x33)/k12),
  Eq(Derivative(x5, t), (1*k12*k20*k65*x4 + (-1)*k12*k21*x5 + (-1)*k12*(k31*x5*x10 - k32*x19) + (-1)*k12*(k44*x5*x25 - k45*x26) + (-1)*k12*(k50*x5*x28 - k51*x30))/k12),
  Eq(Derivative(x6, t), 0),
  Eq(Derivative(x7, t), ((-1)*k12*(k1*x7*x18 - k6*x15) + (-1)*k12*(k1*x29*x7 - k6*x34))/k12),
  Eq(Derivative(x8, t), (1*k12*k22*k64*x7 + (-1)*k12*k23*x8 + 1*k12*k7*k64*x15 + 1*k12*k7*k64*x34)/k12),
  Eq(Derivative(x9, t), (1*k12*k24*k65*x8 + (-1)*k12*k25*x9 + (-1)*k12*(k28*x10*x9 - k29*x18) + (-1)*k12*(k47*x9*x28 - k48*x29))/k12),
  Eq(Derivative(x10, t), ((-1)*k12*(k28*x10*x9 - k29*x18) + 1*k12*k30*x18 + (-1)*k12*(k31*x5*x10 - k32*x19) + 1*k12*k33*x19 + (-1)*k12*x12*k34*x10/k35/(1 + x10/k35 + x25/k36 + x28/k37) + 1*k12*(k38*k68 - k39*x10) + 1*(k42*x36 - k43*x10))/k12),
  Eq(Derivative(x11, t), ((-1)*k12*(k1*x11*x19 - k2*x16) + (-1)*k12*(k1*x11*x26 - k2*x27) + (-1)*k12*(k1*x11*x30 - k2*x32))/k12),
  Eq(Derivative(x12, t), (1*k12*k16*k65*x13 + (-1)*k12*k17*x12)/k12),
  Eq(Derivative(x13, t), (1*k12*k14*k64*x11 + (-1)*k12*k15*x13 + 1*k12*k3*k64*x16 + 1*k12*k3*k64*x27 + 1*k12*k3*k64*x32)/k12),
  Eq(Derivative(x14, t), (1*k12*k26*k64*x21 + (-1)*k12*k27*x14 + 1*k12*k8*k64*x20 + 1*k12*k8*k64*x35)/k12),
  Eq(Derivative(x15, t), 1*k12*(k1*x7*x18 - k6*x15)/k12),
  Eq(Derivative(x16, t), 1*k12*(k1*x11*x19 - k2*x16)/k12),
  Eq(Derivative(x17, t), 1*k12*(k1*x3*x18 - k4*x17)/k12),
  Eq(Derivative(x18, t), (1*k12*(k28*x10*x9 - k29*x18) + (-1)*k12*k30*x18 + (-1)*k12*(k1*x3*x18 - k4*x17) + (-1)*k12*(k1*x7*x18 - k6*x15) + (-1)*k12*(k1*x21*x18 - k5*x20))/k12),
  Eq(Derivative(x19, t), (1*k12*(k31*x5*x10 - k32*x19) + (-1)*k12*k33*x19 + (-1)*k12*(k1*x11*x19 - k2*x16))/k12),
  Eq(Derivative(x20, t), 1*k12*(k1*x21*x18 - k5*x20)/k12),
  Eq(Derivative(x21, t), ((-1)*k12*(k1*x21*x18 - k5*x20) + (-1)*k12*(k1*x29*x21 - k5*x35))/k12),
  Eq(Derivative(x22, t), 0),
  Eq(Derivative(x23, t), 0),
  Eq(Derivative(x24, t), ((-1)*k12*k40*x24 + 1*k12*k41*k65*x14)/k12),
  Eq(Derivative(x25, t), ((-1)*k12*(k44*x5*x25 - k45*x26) + 1*k12*k46*x26)/k12),
  Eq(Derivative(x26, t), (1*k12*(k44*x5*x25 - k45*x26) + (-1)*k12*k46*x26 + (-1)*k12*(k1*x11*x26 - k2*x27))/k12),
  Eq(Derivative(x27, t), 1*k12*(k1*x11*x26 - k2*x27)/k12),
  Eq(Derivative(x28, t), ((-1)*k12*(k47*x9*x28 - k48*x29) + 1*k12*k49*x29 + (-1)*k12*(k50*x5*x28 - k51*x30) + 1*k12*k52*x30 + (-1)*k12*x12*k53*x28/k54/(1 + x28/k54 + x25/k55 + x10/k56) + 1*(k57*k70 - k58*x28))/k12),
  Eq(Derivative(x29, t), (1*k12*(k47*x9*x28 - k48*x29) + (-1)*k12*k49*x29 + (-1)*k12*(k1*x29*x3 - k4*x33) + (-1)*k12*(k1*x29*x7 - k6*x34) + (-1)*k12*(k1*x29*x21 - k5*x35))/k12),
  Eq(Derivative(x30, t), (1*k12*(k50*x5*x28 - k51*x30) + (-1)*k12*k52*x30 + (-1)*k12*(k1*x11*x30 - k2*x32))/k12),
  Eq(Derivative(x31, t), 0),
  Eq(Derivative(x32, t), 1*k12*(k1*x11*x30 - k2*x32)/k12),
  Eq(Derivative(x33, t), 1*k12*(k1*x29*x3 - k4*x33)/k12),
  Eq(Derivative(x34, t), 1*k12*(k1*x29*x7 - k6*x34)/k12),
  Eq(Derivative(x35, t), 1*k12*(k1*x29*x21 - k5*x35)/k12),
  Eq(Derivative(x36, t), ((-1)*(k42*x36 - k43*x10) + (-1)*k13*(k59*x36*x38 - k60*x39) + (-1)*k13*(k61*x40*x36 - k62*x41) + 1*k13*k63*k71)/k13),
  Eq(Derivative(x37, t), 0),
  Eq(Derivative(x38, t), (-1)*k13*(k59*x36*x38 - k60*x39)/k13),
  Eq(Derivative(x39, t), 1*k13*(k59*x36*x38 - k60*x39)/k13),
  Eq(Derivative(x40, t), (-1)*k13*(k61*x40*x36 - k62*x41)/k13),
  Eq(Derivative(x41, t), 1*k13*(k61*x40*x36 - k62*x41)/k13),
  Eq(Derivative(x42, t), 0) ]