Fred-Rik. I believe the states do have the rights to set up elections anyway they want. So they can, at any time, move to a PR system or even a TDG system.

I just want to point out that I have no idea what this particular clause means. It is vague and can be interpreted in many ways. There is a lot of vagueness in this document and its amendments. Maybe its original meaning has been lost as time passed.