[ Eq(Derivative(x1, t), (1*k25*Piecewise((41/1000, Eq(k24, 0)), (33/1000, True)) + 1*k25*Piecewise((11/200000, Eq(k24, 0)), (11/100000, True))*(x1 + x2 + x3 + x4) + 1*k25*Piecewise((27/10000, Eq(k24, 0)), (11/20000, True))*x4 + (-1)*k25*Piecewise((33/100, Eq(k24, 0)), (1/2, True))*(x5 + x6 + x7)*Piecewise((43/10, Eq(k24, 0)), (19, True))/(Piecewise((33/100, Eq(k24, 0)), (1/2, True))*(x5 + x6 + x7) + Piecewise((43/10, Eq(k24, 0)), (19, True))*(x1 + x2 + x3 + x4))*Piecewise((11/500, Eq(k24, 0)), (11/500, True))*x7/(x5 + x6 + x7)*x1 + (-1)*k25*(Piecewise((11/1250000, Eq(k24, 0)), (1/62500, True)) + Piecewise((1/5000000, Eq(k24, 0)), (3/10000000, True))*(x1 + x2 + x3 + x4))*x1)/k25),
  Eq(Derivative(x2, t), (1*k25*Piecewise((33/100, Eq(k24, 0)), (1/2, True))*(x5 + x6 + x7)*Piecewise((43/10, Eq(k24, 0)), (19, True))/(Piecewise((33/100, Eq(k24, 0)), (1/2, True))*(x5 + x6 + x7) + Piecewise((43/10, Eq(k24, 0)), (19, True))*(x1 + x2 + x3 + x4))*Piecewise((11/500, Eq(k24, 0)), (11/500, True))*x7/(x5 + x6 + x7)*x1 + (-1)*k25*Piecewise((1/10, Eq(k24, 0)), (1/10, True))*x2 + (-1)*k25*(Piecewise((11/1250000, Eq(k24, 0)), (1/62500, True)) + Piecewise((1/5000000, Eq(k24, 0)), (3/10000000, True))*(x1 + x2 + x3 + x4))*x2)/k25),
  Eq(Derivative(x3, t), (1*k25*Piecewise((1/10, Eq(k24, 0)), (1/10, True))*x2 + (-1)*k25*Piecewise((7/2000, Eq(k24, 0)), (7/2000, True))*x3 + (-1)*k25*Piecewise((9/500000, Eq(k24, 0)), (9/100000, True))*x3 + (-1)*k25*(Piecewise((11/1250000, Eq(k24, 0)), (1/62500, True)) + Piecewise((1/5000000, Eq(k24, 0)), (3/10000000, True))*(x1 + x2 + x3 + x4))*x3)/k25),
  Eq(Derivative(x4, t), ((-1)*k25*Piecewise((27/10000, Eq(k24, 0)), (11/20000, True))*x4 + 1*k25*Piecewise((7/2000, Eq(k24, 0)), (7/2000, True))*x3 + (-1)*k25*(Piecewise((11/1250000, Eq(k24, 0)), (1/62500, True)) + Piecewise((1/5000000, Eq(k24, 0)), (3/10000000, True))*(x1 + x2 + x3 + x4))*x4)/k25),
  Eq(Derivative(x5, t), (1*k26*Piecewise((13/100, Eq(k24, 0)), (13/100, True))*(x5 + x6 + x7) + (-1)*k26*Piecewise((33/100, Eq(k24, 0)), (1/2, True))*Piecewise((43/10, Eq(k24, 0)), (19, True))*(x1 + x2 + x3 + x4)/(Piecewise((33/100, Eq(k24, 0)), (1/2, True))*(x5 + x6 + x7) + Piecewise((43/10, Eq(k24, 0)), (19, True))*(x1 + x2 + x3 + x4))*(Piecewise((6/25, Eq(k24, 0)), (12/25, True))*x3/(x1 + x2 + x3 + x4) + Piecewise((3/125, Eq(k24, 0)), (6/125, True))*x4/(x1 + x2 + x3 + x4))*x5 + (-1)*k26*(Piecewise((33/1000, Eq(k24, 0)), (33/1000, True)) + Piecewise((1/25000, Eq(k24, 0)), (1/50000, True))*(x5 + x6 + x7))*x5)/k26),
  Eq(Derivative(x6, t), (1*k26*Piecewise((33/100, Eq(k24, 0)), (1/2, True))*Piecewise((43/10, Eq(k24, 0)), (19, True))*(x1 + x2 + x3 + x4)/(Piecewise((33/100, Eq(k24, 0)), (1/2, True))*(x5 + x6 + x7) + Piecewise((43/10, Eq(k24, 0)), (19, True))*(x1 + x2 + x3 + x4))*(Piecewise((6/25, Eq(k24, 0)), (12/25, True))*x3/(x1 + x2 + x3 + x4) + Piecewise((3/125, Eq(k24, 0)), (6/125, True))*x4/(x1 + x2 + x3 + x4))*x5 + (-1)*k26*Piecewise((83/1000, Eq(k24, 0)), (91/1000, True))*x6 + (-1)*k26*(Piecewise((33/1000, Eq(k24, 0)), (33/1000, True)) + Piecewise((1/25000, Eq(k24, 0)), (1/50000, True))*(x5 + x6 + x7))*x6)/k26),
  Eq(Derivative(x7, t), (1*k26*Piecewise((83/1000, Eq(k24, 0)), (91/1000, True))*x6 + (-1)*k26*(Piecewise((33/1000, Eq(k24, 0)), (33/1000, True)) + Piecewise((1/25000, Eq(k24, 0)), (1/50000, True))*(x5 + x6 + x7))*x7)/k26) ]