[Texmacs-dev] PAR_HOR_SEP question

[skhilji]

Apparently PAR_HOR_SEP is only used when when compute the shoevability of a 
Phrase box with the previous Phrase box added to the stacker under the 
circumstances that the new Phrase box is too high or the previous phrase box is 
too low compared to all others added to the stacker before.

Shoevability has to do with the vertical space between two phrase boxes such 
that the boxes that do not touch each other and maintain a minimum vertical 
distance.

It is confusing to the reader as to why we are using a horizontal distance into 
a computation that is purely vertical.