[texhax] xr-hyper,

[Victor Ivrii]

I have been using hyperref and xr-hyper for a while but today I got a
strange problem:

Just placing in preamble

\externaldocument[IRO3-]{IRO3}[http://www.math.toronto.edu/ivrii/Research/preprints/IRO3.pdf]

led me to an error

Undefined control sequence
``Comparing ${\tilde {\cal E}}^\MW....



This is the title of subsection in the paper I am referring to and it
was thus placed to IRO3.aux
I never before used IRO3 as the target. However I used other papers
with the same preamble this way.

This was persistent error: no matter how many times I trashed all
auxiliary files for both the current and the target articles, it was


However, placing definition of \MW   before line

\externaldocument[IRO3-]{IRO3}[http://www.math.toronto.edu/ivrii/Research/preprints/IRO3.pdf]

fixed the problem.

I am a bit confused by this behavior even if I know the fix. Is it documented?

                                         Victor

========================
Victor Ivrii, Department of Mathematics, University of Toronto
http://www.math.toronto.edu/ivrii