[Xy-pic] Revisiting alignment problems

[Henning Makholm]

Scripsit Michael Abbott <michael at araneidae.co.uk>

> to adding the following line to my macro file with largely good results:
> 	\entrymodifiers={+!!<0pt,\fontdimen22\textfont2>}
> However, I have encountered a quirk that I can't see a solution to; can
> anyone else explain what's happening here?

With your entrymodifiers, the empty entry that you're using to break
your arrow still has its emptyness centered around the *baseline*
(because that's the kind of empty boxes TeX produces from \hbox{$$}).
Therefore it ends up below the axis where the horizontal arrow passes
through.

It ought to help to bypass the \entrymodifiers for that cell by doing
something like

      \ar@{-}[rr] & *+{} & \\

-- 
Henning Makholm                              "En tapper tinsoldat. En dame i
                                         spagat. Du er en lykkelig mand ..."