\[\begin{array}{c} \left(x_{1}\rightarrow x_{2}\right)\wedge\left(x_{2}\rightarrow x_{3}\right)\wedge\left(x_{3}\rightarrow x_{4}\right)\wedge\left(x_{4}\rightarrow x_{5}\right),\\ \left(\left(x_{6}\equiv x_{7}\right)\rightarrow x_{8}\right)\wedge\left(\left(x_{9}\equiv x_{10}\right)\rightarrow x_{11}\right)\wedge\left(\left(x_{12}\equiv x_{13}\right)\rightarrow x_{14}\right),\\ x_{4}\equiv\lnot x_{11} \end{array}\]