inter and div levels

The witty exchange between Lou and Sebastian prompts me to ask Lou, now
back from holidaying, if he would kindly provide a neat little
disquisition on the element classes "inter" and "divn" [my copy of the P3
Guidelines being blank at page 780 -- I know I should consult P4 online].

The index to P3 does indicate that there are three div-related classes
(in alphabetical order):

divbot
divn
divtop

Yup, I checked P5 -- no "div" class (Yes, I know that the "divn" class
references <div> elements )

I am being a little stickler for a good reason. Would knowledge of divbot
and divtop classes help some encoders trying to place that extra <div>
after a <p>?

At present the Guidelines present the element classes atomistically (as a
descriptive alphabetical listing). Does anyone have a nice chart depicting
the relations between the various classes? If I read P4, correctly <ab> is
a member of the "chunk" and "typed" classes. Lou perhaps can enlighten me
as to the differences between ~levels~ and ~classes~. I am
partially perplexed by the following statement. I understand that <salute>
and <ab type="salute"> are equivalent but <div type="salute"> would be
possible, no, in a <div> within <div> use case? ...

> Certainly not. They would, if anything, be <ab type="salute"> elements,
> since they are all inter level, not div level. I'm surprised at you!
>
> L

Fascinating game of translate this into that.

-- Francois Lachance, Scholar-at-large
http://www.chass.utoronto.ca/~lachance

Wondering if...

        mnemonic is to analytic
                 as
        mimetic  is to synthetic