{ diff(x1, t) = (1*k26*(7/2 - x1)*k25 + (-1)*k26*k1*x1*x4/((k2 + x4)*(k3 + x1)) + (-1)*k26*k4*x1*x5^2/((k5*(1 + k6*(x1/x3)^2) + x5^2)*(k7 + x1)) + 1*k26*(k13*x10*x2 - k14*x11*x1) + 1*k26*k15*x2*x11/((k16 + x11)*(k17 + x2)) + (-1)*k26*(k22*x3*x1 - k23*x2^2))/k26,
  diff(x2, t) = (1*k26*(11/10 - x2)*k25 + 1*k26*k1*x1*x4/((k2 + x4)*(k3 + x1)) + 1*k26*k4*x1*x5^2/((k5*(1 + k6*(x1/x3)^2) + x5^2)*(k7 + x1)) + (-1)*k26*(k13*x10*x2 - k14*x11*x1) + (-1)*k26*k15*x2*x11/((k16 + x11)*(k17 + x2)) + 2*k26*(k22*x3*x1 - k23*x2^2))/k26,
  diff(x3, t) = ((-1)*k26*x3*k25 + (-1)*k26*(k22*x3*x1 - k23*x2^2))/k26,
  diff(x4, t) = (1*k26*(50 - x4)*k25 + (-1)*k26*k1*x1*x4/((k2 + x4)*(k3 + x1)))/k26,
  diff(x5, t) = ((-1)*k26*x5*k25 + 1*k26*k1*x1*x4/((k2 + x4)*(k3 + x1)) + (-1)*k26*k4*x1*x5^2/((k5*(1 + k6*(x1/x3)^2) + x5^2)*(k7 + x1)) + (-1)*k26*k24*x5)/k26,
  diff(x6, t) = ((-1)*k26*x6*k25 + 1*k26*k4*x1*x5^2/((k5*(1 + k6*(x1/x3)^2) + x5^2)*(k7 + x1)) + (-1)*k26*(k8*x6 - k9*x7^2))/k26,
  diff(x7, t) = ((-1)*k26*x7*k25 + 2*k26*(k8*x6 - k9*x7^2) + (-1)*k26*k10*x8*x7/((k11 + x7)*(k12 + x8)))/k26,
  diff(x8, t) = (1*k26*(4 - x8)*k25 + (-1)*k26*k10*x8*x7/((k11 + x7)*(k12 + x8)) + 1*k26*(k20*x9*x13 - k21*x8*x14))/k26,
  diff(x9, t) = (1*k26*(6/25 - x9)*k25 + 1*k26*k10*x8*x7/((k11 + x7)*(k12 + x8)) + (-1)*k26*(k20*x9*x13 - k21*x8*x14))/k26,
  diff(x10, t) = ((-1)*k26*x10*k25 + 1*k26*k10*x8*x7/((k11 + x7)*(k12 + x8)) + (-1)*k26*(k13*x10*x2 - k14*x11*x1))/k26,
  diff(x11, t) = ((-1)*k26*x11*k25 + 1*k26*(k13*x10*x2 - k14*x11*x1) + (-1)*k26*k15*x2*x11/((k16 + x11)*(k17 + x2)))/k26,
  diff(x12, t) = ((-1)*k26*x12*k25 + 1*k26*k15*x2*x11/((k16 + x11)*(k17 + x2)) + (-1)*k26*k18*x12/(k19 + x12))/k26,
  diff(x13, t) = ((-1)*k26*x13*k25 + 1*k26*k18*x12/(k19 + x12) + (-1)*k26*(k20*x9*x13 - k21*x8*x14))/k26,
  diff(x14, t) = ((-1)*k26*x14*k25 + 1*k26*(k20*x9*x13 - k21*x8*x14))/k26,
  diff(x15, t) = ((-1)*k26*x15*k25 + 1*k26*k24*x5)/k26 }