- TeX source:
- \begin{array}{rclcl} \mathbb{D} &=& \mathbb{R} \cr\cr 8\left(\dfrac{3}{8}x^4-6\right) &=& 3\left(x^2-4\right)\left(x^2+4\right) \cr 3x^4-48 &=& 3\left(x^4-16\right) \cr3x^4-48 &=& 3x^4-48 &\vert& -3x^4+48 \cr0 &=& 0 \cr\cr\mathbb{L} &=& \mathbb{R}\end{array}