\frac{dx_{1}}{dt} = \left(1 \cdot k_{19} \cdot k_{1} \cdot x_{1} \cdot \left(1 - x_{1} / k_{2}\right) + -1 \cdot k_{19} \cdot k_{3} \cdot x_{1} \cdot x_{2} + -1 \cdot k_{19} \cdot k_{9} \cdot x_{1} \cdot x_{3} / \left(k_{11} + x_{3}\right)\right) / k_{19}\\
\frac{dx_{2}}{dt} = \left(1 \cdot k_{19} \cdot k_{5} + -1 \cdot k_{19} \cdot k_{6} \cdot x_{2} + 1 \cdot k_{19} \cdot k_{7} \cdot x_{1} \cdot x_{2} / \left(k_{8} + x_{1}\right) + -1 \cdot k_{19} \cdot k_{4} \cdot x_{1} \cdot x_{2} + -1 \cdot k_{19} \cdot k_{10} \cdot x_{2} \cdot x_{3} / \left(k_{12} + x_{3}\right) + 1 \cdot k_{19} \cdot k_{14}\right) / k_{19}\\
\frac{dx_{3}}{dt} = \left(-1 \cdot k_{19} \cdot k_{13} \cdot x_{3} + 1 \cdot k_{19} \cdot \operatorname{piecewise}(k_{17} / \left(1 / 8\right), t \le 1 / 8, \operatorname{piecewise}(k_{17} / \left(1 / 8\right), \operatorname{and}\left(t \ge 21, t \le 21 + 1 / 8\right), \operatorname{piecewise}(k_{17} / \left(1 / 8\right), \operatorname{and}\left(t \ge 42, t \le 42 + 1 / 8\right), \operatorname{piecewise}(k_{17} / \left(1 / 8\right), \operatorname{and}\left(t \ge 63, t \le 63 + 1 / 8\right), \operatorname{piecewise}(k_{17} / \left(1 / 8\right), \operatorname{and}\left(t \ge 84, t \le 84 + 1 / 8\right), \operatorname{piecewise}(k_{17} / \left(1 / 8\right), \operatorname{and}\left(t \ge 105, t \le 105 + 1 / 8\right), \operatorname{piecewise}(k_{17} / \left(1 / 8\right), \operatorname{and}\left(t \ge 126, t \le 126 + 1 / 8\right), 0)))))))\right) / k_{19}