\frac{dx_{1}}{dt} = 0\\ \frac{dx_{2}}{dt} = \left(1 \cdot k_{20} \cdot k_{17} \cdot k_{15} / k_{16} \cdot k_{21} / k_{6}^{k_{2}} / \left(1 + k_{21} / k_{6}^{k_{2}}\right) + -1 \cdot k_{20} \cdot k_{18} \cdot k_{15} / k_{16} \cdot x_{3} / k_{7}^{k_{12} - \left(k_{12} - k_{13}\right) \cdot x_{4} / k_{8} / \left(1 + x_{4} / k_{8}\right)} / \left(x_{3} / k_{7}^{k_{12} - \left(k_{12} - k_{13}\right) \cdot x_{4} / k_{8} / \left(1 + x_{4} / k_{8}\right)} + \left(1 + x_{4} / k_{9}^{k_{11}}\right) / \left(1 + k_{10}^{k_{12} - \left(k_{12} - k_{13}\right) \cdot x_{4} / k_{8} / \left(1 + x_{4} / k_{8}\right)} \cdot x_{4} / k_{9}^{k_{11}}\right)\right)\right) / k_{20}\\ \frac{dx_{4}}{dt} = \left(1 \cdot k_{20} \cdot k_{18} \cdot k_{15} / k_{16} \cdot x_{3} / k_{7}^{k_{12} - \left(k_{12} - k_{13}\right) \cdot x_{4} / k_{8} / \left(1 + x_{4} / k_{8}\right)} / \left(x_{3} / k_{7}^{k_{12} - \left(k_{12} - k_{13}\right) \cdot x_{4} / k_{8} / \left(1 + x_{4} / k_{8}\right)} + \left(1 + x_{4} / k_{9}^{k_{11}}\right) / \left(1 + k_{10}^{k_{12} - \left(k_{12} - k_{13}\right) \cdot x_{4} / k_{8} / \left(1 + x_{4} / k_{8}\right)} \cdot x_{4} / k_{9}^{k_{11}}\right)\right) + -1 \cdot k_{20} \cdot k_{19} \cdot k_{15} / k_{16} \cdot x_{4} / k_{8} / \left(x_{4} / k_{8} + 1\right)\right) / k_{20}\\ \frac{dx_{5}}{dt} = 0