Love, I gotta keep on moving; love, I gotta get on down.

This simple little knot, shown in black and white and in color, illustrates the principle that my celtic knotwork program ("Knotware") uses. Any (rectangular) celtic knot can be constructed by copying, turning, and flipping the same five basic squares.

If you can draw that basic 2x2 knot, you can draw any knot. Allowing for the different ways that you can rotate the pieces and flip them over, there are 26 different tiles that serve to draw any of these knotwork patterns.

Well, I thought it was interesting, anyway...