x_{4} = x_{1} - x_{2}\\
x_{6} = k_{18} - x_{3}\\
x_{9} = \frac{1}{2} \cdot \left(x_{2} - k_{19} - k_{2} / k_{3} \cdot \left(k_{3} + x_{3} + k_{6} \cdot \left(k_{18} - x_{3}\right)\right) + \sqrt{k_{2} / k_{3} \cdot \left(k_{3} + x_{3} + k_{6} \cdot \left(k_{18} - x_{3}\right)\right) - x_{2} + k_{19}^{2} + 4 \cdot x_{2} \cdot k_{2} / k_{3} \cdot \left(k_{3} + x_{3} + k_{6} \cdot \left(k_{18} - x_{3}\right)\right)}\right)\\
x_{10} = \frac{1}{2} \cdot \left(x_{1} - k_{20} - k_{4} + \sqrt{k_{4} - x_{1} + k_{20}^{2} + 4 \cdot x_{1} \cdot k_{4}}\right)\\
x_{12} = \left(k_{2} + x_{9}\right) / \left(k_{2} / k_{3} \cdot \left(k_{3} + x_{3} + k_{6} \cdot \left(k_{18} - x_{3}\right)\right) + x_{9}\right)\\
x_{13} = x_{2} / \left(k_{5} + x_{1}\right)\\
x_{14} = x_{1} / \left(k_{5} + x_{1}\right)\\
x_{15} = \left(x_{1} - x_{2}\right) / \left(k_{5} + x_{1}\right)\\
x_{16} = x_{3} / k_{18}