\frac{dx_{1}}{dt} = \left(1 \cdot k_{29} \cdot k_{5} \cdot x_{1} + -1 \cdot k_{29} \cdot k_{22} \cdot x_{1} \cdot x_{2} / \left(k_{23} + x_{2}\right)\right) / k_{29}\\
\frac{dx_{2}}{dt} = \left(1 \cdot k_{29} \cdot k_{10} \cdot x_{1} \cdot \left(1 - x_{2} / k_{12}\right) + -1 \cdot k_{29} \cdot k_{21} \cdot x_{2}\right) / k_{29}\\
\frac{dx_{3}}{dt} = \left(1 \cdot k_{29} \cdot k_{1} + -1 \cdot k_{29} \cdot k_{6} \cdot x_{3} + 1 \cdot k_{29} \cdot k_{2} \cdot k_{3} \cdot x_{1}\right) / k_{29}\\
\frac{dx_{4}}{dt} = \left(1 \cdot k_{29} \cdot k_{14} + -1 \cdot k_{29} \cdot k_{11} \cdot x_{4} + 1 \cdot k_{29} \cdot k_{13} \cdot x_{2}\right) / k_{29}