----------o

The easy way to visualize the values of these graphical
expressions is just to notice the following equivalents:

o-------------------------------------------------o
|                                                 |
|  x                                              |
|  o-o-o-...-o-o-o                                |
|   \           /                                 |
|    \         /                                  |
|     \       /                                   |
|      \     /       