add

Here [lambda] has two removable 0-boxes (boxes (2,5) and (4,1)), two removable 1-boxes (boxes (1,8) and (3,4)), no removable 2-boxes, no addable 0-boxes, two addable 1-boxes (in positions (2,6) and (4,2)), and three addable 2-boxes (in positions (1,9), (3,5) and (5,1)).

For a fixed i, (0 [less than or equal to] i < l), we place--in each removable i-box and + in each addable i-box.

The diagram for [lambda] with removable and addable 1-boxes marked is:

Label any addable i-box with a +, and any removable i-box with a -.