This is great but some inclusion of eastern ludology would help round it out.
Thirty spokes meet in the hub. Where the wheel isn’t is where it’s useful.
Hollowed out, clay makes a pot. Where the pot’s not is where it’s useful.
Cut doors and windows to make a room. Where the room isn’t, there’s room for you.
So the profit in what is is in the use of what isn’t.
The whole divides to see the shape.