\frac{dx_{1}}{dt} = 0\\
\frac{dx_{2}}{dt} = \left(1 \cdot k_{1} \cdot k_{14} \cdot k_{2} \cdot k_{12} / k_{3} / \left(1 + k_{12} / k_{3} + x_{2} / k_{4}\right) / \left(1 + k_{13} / k_{5}\right) + -1 \cdot k_{1} \cdot k_{15} \cdot k_{6} \cdot x_{2} / k_{7} / \left(1 + x_{2} / k_{7} + x_{3} / k_{8}\right)\right) / k_{1}\\
\frac{dx_{3}}{dt} = \left(1 \cdot k_{1} \cdot k_{15} \cdot k_{6} \cdot x_{2} / k_{7} / \left(1 + x_{2} / k_{7} + x_{3} / k_{8}\right) + -1 \cdot k_{1} \cdot k_{16} \cdot k_{9} \cdot x_{3} / k_{10} / \left(1 + x_{3} / k_{10} + k_{13} / k_{11}\right)\right) / k_{1}\\
\frac{dx_{4}}{dt} = 0\\
\frac{dx_{5}}{dt} = 0\\
\frac{dx_{6}}{dt} = 0\\
\frac{dx_{7}}{dt} = 0