| · | a | d | b | x1 | x2 | y1 | y2 | u |
|
|
| a | a | 0 | 0 | 0 | 0 | 0 | 0 | 0 | a | a |
| d | 0 | d | 0 | 0 | 0 | d | d | d | 0 | 0 |
| b | 0 | 0 | 0 | b | b | 0 | 0 | b | b | b |
| x1 | 0 | 0 | b | x1 | x2 | b | b | x1 | x1 | x1 |
| x2 | 0 | 0 | b | x2 | x2 | b | b | x2 | x2 | x2 |
| y1 | 0 | d | 0 | b | b | d | d | y1 | b | b |
| y2 | 0 | d | 0 | b | b | d | d | y2 | b | b |
| u | 0 | d | b | x1 | x2 | y1 | y2 | u | x1 | x1 |
|
| a | 0 | b | x1 | x2 | b | b | x1 | v | v |
|
| a | 0 | b | x1 | x2 | b | b | x1 | v | v |