{ diff(x1, t) = 0,
  diff(x2, t) = ((-1)*k1*k4*x2*k2/(x2 + k5*(1 + x3/k6 + x10/k7 + x14/k8 + x8/k9 + k81/k10)) + 1*k1*k36*x17*k2*x4/((x17 + k37*(1 + x3/k38 + x2/k39 + x8/k40))*(x4*(1 + x23/k41) + k42*(1 + x23/k43))))/k2,
  diff(x3, t) = (2*k1*k4*x2*k2/(x2 + k5*(1 + x3/k6 + x10/k7 + x14/k8 + x8/k9 + k81/k10)) + (-1)*k1*k11*k2*(x3*x4 - x5*x23/k12) + (-1)*k67*k68*x3*k2/(k69*(1 + (1 + k70/k82)*(x8/k71 + x3/k69 + x9/k72 + x7/k73))))/k2,
  diff(x4, t) = ((-1)*k1*k11*k2*(x3*x4 - x5*x23/k12) + (-1)*k1*k36*x17*k2*x4/((x17 + k37*(1 + x3/k38 + x2/k39 + x8/k40))*(x4*(1 + x23/k41) + k42*(1 + x23/k43))) + 1*k1*k48*x23*x8*k2/((x23 + k49)*(x8 + k50)) + (-1)*k51*x26*x4*k2/((x26 + k52)*(1 + x23/k53)*(x4 + k54) + k54*x8/(k55*x3) + k56*x11 + k57*x10))/k2,
  diff(x5, t) = (1*k1*k11*k2*(x3*x4 - x5*x23/k12) + (-1)*k1*k13*k2*(x5*k81*k87 - k84*x7*x8/k14))/k2,
  diff(x6, t) = 0,
  diff(x7, t) = (1*k1*k13*k2*(x5*k81*k87 - k84*x7*x8/k14) + (-1)*k2*k15*(x7 - x9/k16) + (-1)*k17*k2*(x9*x7 - x10/k18) + (-1)*k2*k23*(x11*x7 - x12*x13/k24) + (-1)*k2*k30*(x7*x15 - x13*x16/k31) + (-1)*k74*x7*k2/(k75*(1 + (1 + k76/k82)*(x8/k77 + x3/k78 + x9/k79 + x7/k75))))/k2,
  diff(x8, t) = (1*k1*k13*k2*(x5*k81*k87 - k84*x7*x8/k14) + 1*k1*k19*x10*k2/(x10 + k20*(1 + x11/k21 + x8/k22)) + 1*k1*k27*x14*k2/(x14 + k28*(1 + x8/k29)) + (-1)*k1*k48*x23*x8*k2/((x23 + k49)*(x8 + k50)) + 2*k51*x26*x4*k2/((x26 + k52)*(1 + x23/k53)*(x4 + k54) + k54*x8/(k55*x3) + k56*x11 + k57*x10) + (-1)*k58*x8*k2/(x8 + k59*(1 + x26/k60)) + 1*k61*x9*k2/(k62*(1 + (1 + k63/k82)*(x8/k64 + x3/k65 + x9/k62 + x7/k66))) + 1*k67*k68*x3*k2/(k69*(1 + (1 + k70/k82)*(x8/k71 + x3/k69 + x9/k72 + x7/k73))) + 1*k74*x7*k2/(k75*(1 + (1 + k76/k82)*(x8/k77 + x3/k78 + x9/k79 + x7/k75))))/k2,
  diff(x9, t) = (1*k2*k15*(x7 - x9/k16) + (-1)*k17*k2*(x9*x7 - x10/k18) + (-1)*k2*k25*(x12*x9 - x14/k26) + (-1)*k61*x9*k2/(k62*(1 + (1 + k63/k82)*(x8/k64 + x3/k65 + x9/k62 + x7/k66))))/k2,
  diff(x10, t) = (1*k17*k2*(x9*x7 - x10/k18) + (-1)*k1*k19*x10*k2/(x10 + k20*(1 + x11/k21 + x8/k22)))/k2,
  diff(x11, t) = (1*k1*k19*x10*k2/(x10 + k20*(1 + x11/k21 + x8/k22)) + (-1)*k2*k23*(x11*x7 - x12*x13/k24) + (-1)*k44*k2*(x11 - x20/k45))/k2,
  diff(x12, t) = (1*k2*k23*(x11*x7 - x12*x13/k24) + (-1)*k2*k25*(x12*x9 - x14/k26))/k2,
  diff(x13, t) = (1*k2*k23*(x11*x7 - x12*x13/k24) + 1*k2*k30*(x7*x15 - x13*x16/k31) + (-1)*k2*k34*(x13 - x17/k35))/k2,
  diff(x14, t) = (1*k2*k25*(x12*x9 - x14/k26) + (-1)*k1*k27*x14*k2/(x14 + k28*(1 + x8/k29)))/k2,
  diff(x15, t) = (1*k1*k27*x14*k2/(x14 + k28*(1 + x8/k29)) + (-1)*k2*k30*(x7*x15 - x13*x16/k31))/k2,
  diff(x16, t) = (1*k2*k30*(x7*x15 - x13*x16/k31) + (-1)*k32*k2*(x16 - x17/k33))/k2,
  diff(x17, t) = (1*k32*k2*(x16 - x17/k33) + 1*k2*k34*(x13 - x17/k35) + (-1)*k1*k36*x17*k2*x4/((x17 + k37*(1 + x3/k38 + x2/k39 + x8/k40))*(x4*(1 + x23/k41) + k42*(1 + x23/k43))))/k2,
  diff(x18, t) = 0,
  diff(x19, t) = 0,
  diff(x20, t) = (1*k44*k2*(x11 - x20/k45) + (-1)*k46*k2*(x20 - x26/k47))/k2,
  diff(x21, t) = 0,
  diff(x22, t) = 0,
  diff(x23, t) = (1*k1*k11*k2*(x3*x4 - x5*x23/k12) + 1*k1*k36*x17*k2*x4/((x17 + k37*(1 + x3/k38 + x2/k39 + x8/k40))*(x4*(1 + x23/k41) + k42*(1 + x23/k43))) + (-1)*k1*k48*x23*x8*k2/((x23 + k49)*(x8 + k50)) + 1*k51*x26*x4*k2/((x26 + k52)*(1 + x23/k53)*(x4 + k54) + k54*x8/(k55*x3) + k56*x11 + k57*x10))/k2,
  diff(x24, t) = 0,
  diff(x25, t) = 0,
  diff(x26, t) = (1*k46*k2*(x20 - x26/k47) + (-1)*k51*x26*x4*k2/((x26 + k52)*(1 + x23/k53)*(x4 + k54) + k54*x8/(k55*x3) + k56*x11 + k57*x10) + 1*k58*x8*k2/(x8 + k59*(1 + x26/k60)))/k2,
  diff(x27, t) = 0 }