Domain	Roots of $g_{1} (u)$	Roots of $g_{2} (v)$	Accessible region	$A_{ℝ}$
1	0	$v_{1} < 0 < v_{2}$	$\emptyset \times [v_{1}, v_{2}]$	∅
2	$u_{1} < u_{2} < 0 < u_{3} < u_{4}$	$v_{1} < 0 < v_{2}$	$[u_{1}, u_{2}] \cup [u_{3}, u_{4}] \times [v_{1}, v_{2}]$	2T
3	$u_{1} < u_{2} < 0 < u_{3} < u_{4}$	$v_{1} < 0 < v_{2}$	$[u_{1}, u_{2}] \cup [u_{3}, u_{4}] \times [v_{1}, v_{2}]$	2T
4	$u_{1} < 0 < u_{2}$	$v_{1} < 0 < v_{2}$	$[u_{1}, u_{2}] \times [v_{1}, v_{2}]$	T
5	$u_{1} < 0 < u_{2}$	$v_{1} < 0 < v_{2}$	$[u_{1}, u_{2}] \times [v_{1}, v_{2}]$	T
6	$u_{1} < 0 < u_{2}$	$v_{1} < 0 < v_{2}$	$[u_{1}, u_{2}] \times [v_{1}, v_{2}]$	T
7	$u_{1} < 0 < u_{2}$	$v_{1} < 0 < v_{2}$	$[u_{1}, u_{2}] \times [v_{1}, v_{2}]$	T
8	$u_{1} < 0 < u_{2}$	$v_{1} < v_{2} < 0 < v_{3} < v_{4}$	$[u_{1}, u_{2}] \times [v_{1}, v_{2}] \cup [v_{3}, v_{4}]$	2T
9	$u_{1} < 0 < u_{2}$	$v_{1} < v_{2} < 0 < v_{3} < v_{4}$	$[u_{1}, u_{2}] \times [v_{1}, v_{2}] \cup [v_{3}, v_{4}]$	2T
10	$u_{1} < 0 < u_{2}$	0	$[u_{1}, u_{2}] \times \emptyset$	∅