Unclear definition of "pointer-interactable element"

[gsnedders]

In chapter 11. Elements, section 11.1 Element Interactability:

A pointer-interactable element is defined to be the first element, defined by the paint order found at the center point of its rectangle that is inside the viewport, excluding the size of any rendered scrollbars.

I think what this is trying to say is:

An element is pointer-interactable if it is the first element of its paint order found at the center point of its rectangle that is inside the viewport, excluding the size of any rendered scrollbars.

The current spec text makes me not entirely sure if it's saying there is a pointer-interactable element for every element in the document (which may be the same element) or if some elements are pointer-interactable.

[gsnedders]

Also: should we not use the pointer-interactable paint tree here, rather than repeating half of its definition?