{ diff(x1, t) = (1*k5*k2*(k101 - x1)/k6/(1 + (k101 + x1)/k6 + k7*k101*x1/k6^2) + (-1)*k3*k2*k8*(x1*x2/(k9*k10) - x3*x4/(k9*k10*k11))/((1 + x1/k9 + x3/k12)*(1 + x2/k10 + x4/k13)))/k3,
  diff(x2, t) = ((-1)*k3*k2*k8*(x1*x2/(k9*k10) - x3*x4/(k9*k10*k11))/((1 + x1/k9 + x3/k12)*(1 + x2/k10 + x4/k13)) + (-1)*k3*k18*k2*k19*x5/k20*x2/k21*(1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)/((1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)^2 + k22*((1 + k23*x2/k24)/(1 + x2/k24))^2*((1 + k25*x8/k26)/(1 + x8/k26))^2*((1 + k27*k100/k28 + k29*x6/k30)/(1 + k100/k28 + x6/k30))^2*(1 + k31*x2/k21)^2) + 1*k3*k47*k2*(k48*x12*x4 - x14*x2)/(k49*k50)/((1 + x12/k51 + x14/k49)*(1 + x4/k52 + x2/k50)) + 1*k3*k61*k2*(x16*x4/(k62*k63) - x17*x2/(k62*k63*k64))/((1 + x16/k62 + x17/k65)*(1 + x4/k63 + x2/k66)) + (-1)*k3*k80*x2 + 1*k3*(k81*x4*x4 - k82*x2*x8) + (-1)*k3*k89 + (-1)*k3*k90)/k3,
  diff(x3, t) = (1*k3*k2*k8*(x1*x2/(k9*k10) - x3*x4/(k9*k10*k11))/((1 + x1/k9 + x3/k12)*(1 + x2/k10 + x4/k13)) + (-1)*k3*k14*k2*(x3/k15 - x5/(k15*k16))/(1 + x3/k15 + x5/k17) + (-1)*k3*k89 + (-2)*k3*k90)/k3,
  diff(x4, t) = (1*k3*k2*k8*(x1*x2/(k9*k10) - x3*x4/(k9*k10*k11))/((1 + x1/k9 + x3/k12)*(1 + x2/k10 + x4/k13)) + 1*k3*k18*k2*k19*x5/k20*x2/k21*(1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)/((1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)^2 + k22*((1 + k23*x2/k24)/(1 + x2/k24))^2*((1 + k25*x8/k26)/(1 + x8/k26))^2*((1 + k27*k100/k28 + k29*x6/k30)/(1 + k100/k28 + x6/k30))^2*(1 + k31*x2/k21)^2) + (-1)*k3*k47*k2*(k48*x12*x4 - x14*x2)/(k49*k50)/((1 + x12/k51 + x14/k49)*(1 + x4/k52 + x2/k50)) + (-1)*k3*k61*k2*(x16*x4/(k62*k63) - x17*x2/(k62*k63*k64))/((1 + x16/k62 + x17/k65)*(1 + x4/k63 + x2/k66)) + 1*k3*k80*x2 + (-2)*k3*(k81*x4*x4 - k82*x2*x8) + 1*k3*k89 + 1*k3*k90)/k3,
  diff(x5, t) = (1*k3*k14*k2*(x3/k15 - x5/(k15*k16))/(1 + x3/k15 + x5/k17) + (-1)*k3*k18*k2*k19*x5/k20*x2/k21*(1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)/((1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)^2 + k22*((1 + k23*x2/k24)/(1 + x2/k24))^2*((1 + k25*x8/k26)/(1 + x8/k26))^2*((1 + k27*k100/k28 + k29*x6/k30)/(1 + k100/k28 + x6/k30))^2*(1 + k31*x2/k21)^2))/k3,
  diff(x6, t) = (1*k3*k18*k2*k19*x5/k20*x2/k21*(1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)/((1 + x5/k20 + x2/k21 + k19*x5/k20*x2/k21)^2 + k22*((1 + k23*x2/k24)/(1 + x2/k24))^2*((1 + k25*x8/k26)/(1 + x8/k26))^2*((1 + k27*k100/k28 + k29*x6/k30)/(1 + k100/k28 + x6/k30))^2*(1 + k31*x2/k21)^2) + (-1)*k3*k32*k2*(x6/k33 - x9*x10/(k33*k34))/(1 + x6/k33 + x9/k35 + x10/k36 + x6*x10/(k33*k37) + x9*x10/(k35*k36)))/k3,
  diff(x7, t) = 0,
  diff(x8, t) = 1*k3*(k81*x4*x4 - k82*x2*x8)/k3,
  diff(x9, t) = (1*k3*k32*k2*(x6/k33 - x9*x10/(k33*k34))/(1 + x6/k33 + x9/k35 + x10/k36 + x6*x10/(k33*k37) + x9*x10/(k35*k36)) + (-1)*k3*(k38*x9 - k39*x10) + (-1)*k3*k83*k2*(x9/k84*x13/k85 - k104/k84*x11/k85*1/k86)/((1 + x9/k84 + k104/k87)*(1 + x13/k85 + x11/k88)))/k3,
  diff(x10, t) = (1*k3*k32*k2*(x6/k33 - x9*x10/(k33*k34))/(1 + x6/k33 + x9/k35 + x10/k36 + x6*x10/(k33*k37) + x9*x10/(k35*k36)) + 1*k3*(k38*x9 - k39*x10) + (-1)*k3*k40*(k41*k2*x10*x11/(k42*k43) - k44*k2*x12*x13/(k45*k46))/((1 + x10/k42 + x12/k45)*(1 + x11/k43 + x13/k46)))/k3,
  diff(x11, t) = ((-1)*k3*k40*(k41*k2*x10*x11/(k42*k43) - k44*k2*x12*x13/(k45*k46))/((1 + x10/k42 + x12/k45)*(1 + x11/k43 + x13/k46)) + (-1)*k3*k70*k2*(k103*x11/(k71*k72) - x19*x13/(k71*k72*k73))/(1 + x11/k72 + k103*k74/(k72*k71) + x19*k75/(k76*k77) + x13/k76 + k103*x11/(k72*k71) + x11*x19*k75/(k72*k76*k77) + k103*x13*k74/(k72*k76*k71) + x19*x13/(k77*k76) + k103*x11*x19/(k72*k78*k71) + k103*x19*x13/(k79*k76*k77)) + 1*k3*k83*k2*(x9/k84*x13/k85 - k104/k84*x11/k85*1/k86)/((1 + x9/k84 + k104/k87)*(1 + x13/k85 + x11/k88)) + (-3)*k3*k91*x19)/k3,
  diff(x12, t) = (1*k3*k40*(k41*k2*x10*x11/(k42*k43) - k44*k2*x12*x13/(k45*k46))/((1 + x10/k42 + x12/k45)*(1 + x11/k43 + x13/k46)) + (-1)*k3*k47*k2*(k48*x12*x4 - x14*x2)/(k49*k50)/((1 + x12/k51 + x14/k49)*(1 + x4/k52 + x2/k50)))/k3,
  diff(x13, t) = (1*k3*k40*(k41*k2*x10*x11/(k42*k43) - k44*k2*x12*x13/(k45*k46))/((1 + x10/k42 + x12/k45)*(1 + x11/k43 + x13/k46)) + 1*k3*k70*k2*(k103*x11/(k71*k72) - x19*x13/(k71*k72*k73))/(1 + x11/k72 + k103*k74/(k72*k71) + x19*k75/(k76*k77) + x13/k76 + k103*x11/(k72*k71) + x11*x19*k75/(k72*k76*k77) + k103*x13*k74/(k72*k76*k71) + x19*x13/(k77*k76) + k103*x11*x19/(k72*k78*k71) + k103*x19*x13/(k79*k76*k77)) + (-1)*k3*k83*k2*(x9/k84*x13/k85 - k104/k84*x11/k85*1/k86)/((1 + x9/k84 + k104/k87)*(1 + x13/k85 + x11/k88)) + 3*k3*k91*x19)/k3,
  diff(x14, t) = (1*k3*k47*k2*(k48*x12*x4 - x14*x2)/(k49*k50)/((1 + x12/k51 + x14/k49)*(1 + x4/k52 + x2/k50)) + (-1)*k3*k53*k2*(x14/k54 - x15/(k54*k55))/(1 + x14/k54 + x15/k56))/k3,
  diff(x15, t) = (1*k3*k53*k2*(x14/k54 - x15/(k54*k55))/(1 + x14/k54 + x15/k56) + (-1)*k3*k57*k2*(x15/k58 - x16/(k58*k59))/(1 + x15/k58 + x16/k60))/k3,
  diff(x16, t) = (1*k3*k57*k2*(x15/k58 - x16/(k58*k59))/(1 + x15/k58 + x16/k60) + (-1)*k3*k61*k2*(x16*x4/(k62*k63) - x17*x2/(k62*k63*k64))/((1 + x16/k62 + x17/k65)*(1 + x4/k63 + x2/k66)))/k3,
  diff(x17, t) = (1*k3*k61*k2*(x16*x4/(k62*k63) - x17*x2/(k62*k63*k64))/((1 + x16/k62 + x17/k65)*(1 + x4/k63 + x2/k66)) + (-1)*k3*k67*k2*(x17/k68)^k69/(1 + (x17/k68)^k69) + (-1)*k1*(k92*x17 - k93*x18))/k3,
  diff(x18, t) = (1*k1*(k92*x17 - k93*x18) + (-1)*k4*k2*k94*x18*(k95 - k95/(1 + x11/x13))/(k95*k99*k97/k98/(1 + x11/x13) + k96*(k95 - k95/(1 + x11/x13)) + k97*x18 + k95*k97/k98*x18/(1 + x11/x13) + (k95 - k95/(1 + x11/x13))*x18))/k4,
  diff(x19, t) = (1*k3*k67*k2*(x17/k68)^k69/(1 + (x17/k68)^k69) + 1*k3*k70*k2*(k103*x11/(k71*k72) - x19*x13/(k71*k72*k73))/(1 + x11/k72 + k103*k74/(k72*k71) + x19*k75/(k76*k77) + x13/k76 + k103*x11/(k72*k71) + x11*x19*k75/(k72*k76*k77) + k103*x13*k74/(k72*k76*k71) + x19*x13/(k77*k76) + k103*x11*x19/(k72*k78*k71) + k103*x19*x13/(k79*k76*k77)) + (-2)*k3*k91*x19)/k3,
  diff(x20, t) = 0,
  diff(x21, t) = 0,
  diff(x22, t) = 0,
  diff(x23, t) = 0,
  diff(x24, t) = 0,
  diff(x25, t) = 0,
  diff(x26, t) = 0,
  diff(x27, t) = 0,
  diff(x28, t) = 0 }