Cross-referencing in LaTeX.

xref.txt

paper.tex: main manuscript
supp.tex: supplementary material

Cross-referencing
-----------------

We want to cross-reference equations in paper.tex from supp.tex.


Add the following to supp.tex:

\usepackage{xr}
\externaldocument{paper}

Then use \ref, \eqref, \section etc normally.


Equation numbering
------------------

In order for the equation numbering in supp.tex to start from the last equation
in paper.tex, add the following to paper.tex:

\usepackage{newfile}

[...]

\newoutputstream{stream}
\openoutputfile{counters}{stream}
\addtostream{stream}{
  \protect\setcounter{equation}{\arabic{equation}}%
}
\closeoutputstream{stream}

\end{document}

This will save the equation counter to a file named "counters".
Other counters include: part, chapter, section, subsection, subsubsection,
paragraph, subparagraph, page, equation, figure, table, footnote, mpfootnote

Then include the "counters" file in supp.tex:
\input{counters}
\addtocounter{equation}{1}

To get the references correctly, each file must be compiled with pdflatex two
(or three) times.