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