Shape

295 Erasing and Identity
four medium-sized ones
and one large one
And that’s not all I can do. There are other features that help to distinguish context.
For example, I can refine my identity in this way
to add a detail to the square to break its symmetry, and apply the identity again to
reclassify the nine small squares. First, the new identity applies in four different ways
to corners
then in six different ways to outside squares that aren’t corners
and in eight different ways to the central square