  +--------------------------------------+   +--------------------------------------+
  |                                      |   |                                      |
  |                                      |   |                                      |
  |                                      |   |     cBLU not A                       |
  |                                      |   |                                      |
  |          +-------------------+       |   |          +-------------------+       |
  |          |                   |       |   |          |                   |       |
  |          |   cBLU            |       |   |          |                   |       |
  |          |                   |       |   |          |                   |       |
  |          |             A     |       |   |          |             A     |       |
  |          |                   |       |   |          |                   |       |
  |          +-------------------+       |   |          +-------------------+       |
  |                                      |   |                                      |
  +--------------------------------------+   +--------------------------------------+
