i4 : picture C
+----------------------------------------+
|+-------+-------+ |
o4 = || |(1, {})| |
|+-------+-------+ |
||(0, {})| * | |
|+-------+-------+ |
+----------------------------------------+
|+-------+-------+--------+ |
|| |(2, {})|(0, {1})| |
|+-------+-------+--------+ |
||(1, {})| * | * | |
|+-------+-------+--------+ |
+----------------------------------------+
|+--------+--------+--------+ |
|| |(0, {2})|(1, {1})| |
|+--------+--------+--------+ |
|| (2, {})| * | * | |
|+--------+--------+--------+ |
||(0, {1})| . | * | |
|+--------+--------+--------+ |
+----------------------------------------+
|+--------+--------+--------+-----------+|
|| |(1, {2})|(2, {1})|(0, {1, 1})||
|+--------+--------+--------+-----------+|
||(0, {2})| * | . | 1,1 ||
|+--------+--------+--------+-----------+|
||(1, {1})| . | * | * ||
|+--------+--------+--------+-----------+|
+----------------------------------------+
|