# Squares & sticks

tivol at tethys.ph.albany.edu tivol at tethys.ph.albany.edu
Thu Jun 16 08:53:13 EST 1994

```Dear James,
You define RAS as # of times 2 squares share a stick to the exclusion
of a third and RAP score as N-2 where N is # of squares.  Is N = 2?, is N =
25?  Is RAS = RAP?  If two sticks are roughly parallel such that they are
shared between A1 and A2 (upper left corner and top row 2nd square?) is the
RAP for A1, A2 = 2; is the RAS for A1, A2 = 0?  For squares 25 cm on a side
your first diagram is not possible, only your second.  That means to me that
no stick can be found "within a square juxtaposed between two other squares".
Finally, is this diagram where a stick is shared by four squares possible:

|_____|_____|
|     |     |
|_____*_____|
|     *     |
|_____*_____|

or

|_____|_____|
|     | *   |
|_____*_____|
|    *|     |
|_____|_____|

In the last diagram, the stick lies directly on the corner, but my artistic
skills(?) are not up to the task of representing this accurately.
Since, in my understanding, all sticks lying within more than two
squares are not counted, I cannot figure out what it is your colleague is
supposed to find to be independent or not independent.  Please clarify.

Yours,

Bill Tivol

```