\frac{dx_{1}}{dt} = 1 \cdot k_{11} \cdot \left(-k_{3}\right) \cdot x_{1} \cdot \ln\left(\left(x_{1} + x_{2}\right) / k_{1}\right) / k_{11}\\
\frac{dx_{2}}{dt} = 1 \cdot k_{11} \cdot \left(-\left(k_{4} + k_{6} \cdot x_{4} - k_{1}^{2} / \left(k_{5} \cdot x_{4}^{2} + x_{4} - k_{1}^{2}\right)\right)\right) \cdot x_{2} \cdot \ln\left(\left(x_{1} + x_{2}\right) / k_{2}\right) / k_{11}\\
\frac{dx_{3}}{dt} = \left(1 \cdot k_{11} \cdot k_{7} \cdot x_{3} + -1 \cdot k_{11} \cdot k_{8} \cdot x_{3} \cdot x_{2} / \left(k_{9} + x_{2}\right)\right) / k_{11}