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I have a problem compiling the following document.

First, I have a file macros.sty that consists of :


Then, I have an auxiliary file out.aux that consists of :


Finally, the main file is :


The error message is :

./out.aux:1: Undefined control sequence.
\xymatrix@R ->\Addop@@ 
                   \xymatrixrowsep@ \dimen@ii 

Note that if you remove the R=0mm, the problem no longer holds.

Is that a bug ?

It is very strange because I remember to have already used a command similar to \test in an input file without any problem.

Does it come from my distribution ?

Thank you :)

share|improve this question
I agree with you --- but, actually, some of my questions didn't get a satisfying answer, imo. (Even though these answers are interesting and nice) – Colas Oct 18 '11 at 16:03
up vote 6 down vote accepted

The problem is that .sty files are read with an implicit \makeatletter command, so your input is interpreted as the command \xymatrix@R and not as \xymatrix followed by @. Either write


or move the definition of \test to a file that you load with \input and not with \usepackage.

share|improve this answer
Clear and nice answer ! Apart from this @-matter, what's the difference between \input and \usepackage ? Should I prefer \usepackage for my commands ? – Colas Oct 18 '11 at 16:04
Your idea works but I dont understand why there is no problem if I execute directly in the .tex file the command \test. – Colas Oct 18 '11 at 16:08
@Colas I get the same error both with \input and writing \test directly in the file. I'd recommend \input for your macros. – egreg Oct 18 '11 at 16:14

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