/ ___ ___\ / ___ ___\
|\/ 2 - \/ 6 | |\/ 2 + \/ 6 | pi
[0, -atan|-------------|) U (-atan|-------------|, --]
| ___ ___| | ___ ___| 2
\\/ 2 + \/ 6 / \\/ 2 - \/ 6 /
$$x\ in\ \left[0, - \operatorname{atan}{\left(\frac{- \sqrt{6} + \sqrt{2}}{\sqrt{2} + \sqrt{6}} \right)}\right) \cup \left(- \operatorname{atan}{\left(\frac{\sqrt{2} + \sqrt{6}}{- \sqrt{6} + \sqrt{2}} \right)}, \frac{\pi}{2}\right]$$
x in Union(Interval.Ropen(0, -atan((-sqrt(6) + sqrt(2))/(sqrt(2) + sqrt(6)))), Interval.Lopen(-atan((sqrt(2) + sqrt(6))/(-sqrt(6) + sqrt(2))), pi/2))
/ / / ___ ___\\ / / ___ ___\ \\
| | |\/ 6 - \/ 2 || | pi |\/ 2 + \/ 6 | ||
Or|And|0 <= x, x < atan|-------------||, And|x <= --, atan|-------------| < x||
| | | ___ ___|| | 2 | ___ ___| ||
\ \ \\/ 2 + \/ 6 // \ \\/ 6 - \/ 2 / //
$$\left(0 \leq x \wedge x < \operatorname{atan}{\left(\frac{- \sqrt{2} + \sqrt{6}}{\sqrt{2} + \sqrt{6}} \right)}\right) \vee \left(x \leq \frac{\pi}{2} \wedge \operatorname{atan}{\left(\frac{\sqrt{2} + \sqrt{6}}{- \sqrt{2} + \sqrt{6}} \right)} < x\right)$$
((0 <= x)∧(x < atan((sqrt(6) - sqrt(2))/(sqrt(2) + sqrt(6)))))∨((x <= pi/2)∧(atan((sqrt(2) + sqrt(6))/(sqrt(6) - sqrt(2))) < x))