# [Xy-pic] xy-pic arrow problem

Michael Barr barr at math.mcgill.ca
Sun Sep 18 14:29:09 CEST 2011

I don't know what you are doing wrong, but I got an error message (not the
same error message, but an error message) when running the same file.  I
once learned all the xy syntax needed to program a front end, diagxy, but
have since forgot it.  But the following runs perfectly:

\documentclass{article}
\pdfoutput0
\usepackage[matrix]{xy}
\input diagxy
\begin{document}

% $\xymatrix{R\ar@{-->}[r] B}$
$\bfig \morphism/-->/[AB;]\efig$
\end{document}

You can even more simply use

$R\to/-->/B$

Probably you will find the first arrow longer than you want and the second
shorter, but either can be adjusted easily.

Diagxy is available from CTAN.

Michael
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