Thank you for the compliments. I think there is some inconsistency in the question by Leitz, but I simply chose to start the indices at 1 in my answer and I tried to be consistent with it. Probably 0 would have been a better choice as that is the choice in the referenced paper.

You're right. So I guess one should replace "free" by "as free as it can possibly be". However, here my own intuition ends.