+-----+-----+---+------------+-------------+
| a   | b   | i | x          | y           |
+-----+-----+---+------------+-------------+
| pan | pan | 1 | 0.34679014 | 0.72680286  |
| eks | pan | 2 | 0.75867996 | -0.52215111 |
| wye | wye | 3 | 0.20460331 | 0.33831853  |
| eks | wye | 4 | 0.38139939 | -0.13418874 |
+-----+-----+---+------------+-------------+

+-----+-----+---+------------+-------------+
| a   | b   | i | x          | y           |
+-----+-----+---+------------+-------------+
| wye | pan | 5 | 0.57328892 | 0.86362447  |
| zee | pan | 6 | 0.52712616 | -0.49322129 |
| eks | zee | 7 | 0.61178406 | 0.18788492  |
| zee | wye | 8 | 0.59855401 | 0.97618139  |
+-----+-----+---+------------+-------------+

+-----+-----+----+------------+-------------+
| a   | b   | i  | x          | y           |
+-----+-----+----+------------+-------------+
| hat | wye | 9  | 0.03144188 | -0.74955076 |
| pan | wye | 10 | 0.50262601 | 0.95261836  |
+-----+-----+----+------------+-------------+
