[aesthesia]

I think there's an error here in the case of a very tall notebook. The paper claims that there is a finite limit to how far to the right the bookmark can go. But it seems to me that for a sufficiently tall sheet of paper, the optimal fold is at a 45 degree angle with the left edge of the paper folded right up to the top edge. This gives you a length of D - 1 hanging to the right, where the width of the paper is 1 and the height is D.

[skykooler]

I believe "tall" here refers to the length of the spine of the notebook, in which nomenclature what you're referring to is a "wide" paper.

[jws]

Isn’t this the special case covered near the top of page 8?