Category talk:Patterns with C2 symmetry

I think that there are three separate types of C2 symentry when applied to a square grid.

1. The rotation point can be centered on a vertex or the point between four cells. The snake is an example.
2. The rotation point can be centered on an edge or the point between two cells. The aircraft carrier is an example.
3. The rotation point can be centered on a cell. The 50P35 is an example.

Perhaps three separate categories would be appropriate.--Scot Ellison 07:58, 6 July 2011 (CDT)