[Xy-pic] What are the default entry modifiers in xygraph, xymatrix, and xymatrix@1?

[Alexander Perlis]

When you process

  \xymatrix{A \ar[r] & B}

you discover that Xy-pic places nice margins around "A" and "B" so
that the arrows do not get too close to the objects. Similarly, using
\xygraph{...}, you get those same margins. If you instead use
\xymatrix@1{A \ar[r] & B} then the margins will be smaller.

Sometimes one wishes to build more complicated entries, which
sometimes requires escaping to Xy-pic kernel code. But I would like
to maintain the precise same margins as would have been used above!
So my question is simply: what modifiers do the job?

In my experiments, it seems that the "+" modifier gives the same
margins as \xymatrix and \xygraph, but I'm not certain. In other
words, *+{A} seems to produce the same "A" as the code above does.
But in addition to getting confirmation, I wonder, what modifiers
precisely mimic the behavior of \xymatrix@1{...}?

Thanks.


__________________________________________________
Do You Yahoo!?
Yahoo! Finance - Get real-time stock quotes
http://finance.yahoo.com