TeX source:
\begin{array}{rcl} -10 &=& -4 \cdot\left\vert \left(6 \cdot \left(-\dfrac{1}{2}\right)+5\right)\cdot\left(-26 \cdot \left(-\dfrac{1}{2}\right)-13\right)\right\vert -10 \cr -10 &=& -4 \cdot\vert 0\vert -10 \cr -10 &=& -10 \end{array}