$\left\{\begin{matrix}F_{6}=-\frac{1+z-y-x^{2}}{ϕ}\text{, }&ϕ\neq 0\\F_{6}\in \mathrm{C}\text{, }&z=x^{2}+y-1\text{ and }ϕ=0\end{matrix}\right.$

$\left\{\begin{matrix}F_{6}=-\frac{1+z-y-x^{2}}{ϕ}\text{, }&ϕ\neq 0\\F_{6}\in \mathrm{R}\text{, }&z=x^{2}+y-1\text{ and }ϕ=0\end{matrix}\right.$

$x=-\sqrt{1+F_{6}ϕ+z-y}$
$x=\sqrt{1+F_{6}ϕ+z-y}$

$x=\sqrt{1+F_{6}ϕ+z-y}$
$x=-\sqrt{1+F_{6}ϕ+z-y}\text{, }z\geq -\left(1+F_{6}ϕ-y\right)$