# Undefined control sequence with xparse

I just installed the texlive-latex3 package and tried running pdflatex on the following (copied directly from another question posted here):

\documentclass{article}
\usepackage{xparse}
\ExplSyntaxOn
\NewDocumentCommand {\dothings}
{ > { \SplitList { ~ } } m }
{ \tl_map_inline:nn {#1} { \fbox{##1} } }
\ExplSyntaxOff
\begin{document}
\dothings{Takes several words as argument}
\end{document}

But I'm getting an "Undefined control sequence" error. The same happens with any other code I copy that uses xparse. What am I doing wrong here? I've noticed that it says I'm using LaTeX2e. Could that be related to the issue?

This is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian)
entering extended mode
(./test.tex
LaTeX2e <2009/09/24>
Babel <v3.8l> and hyphenation patterns for english, usenglishmax, dumylang, noh
(/usr/share/texmf-texlive/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/usr/share/texmf-texlive/tex/latex/base/size10.clo))
(/usr/share/texmf-texlive/tex/latex/xpackages/xbase/xparse.sty
(/usr/share/texmf-texlive/tex/latex/expl3/l3names.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/expl3.sty
(/usr/share/texmf-texlive/tex/latex/expl3/l3basics.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3expan.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3tl.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3num.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3intexpr.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3quark.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3seq.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3toks.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3int.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3prg.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3clist.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3token.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3io.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3prop.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3msg.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3skip.sty))
(/usr/share/texmf-texlive/tex/latex/expl3/l3box.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3keyval.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3keys.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3precom.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3calc.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3xref.sty)
(/usr/share/texmf-texlive/tex/latex/expl3/l3file.sty)) (./test.aux)
! Undefined control sequence.
\xparse_processor_1:n #1->\SplitList
{ }{#1}
l.9 \dothings{Takes several words as argument}

?
-
Can you post the output of \listfiles? – Bruno Le Floch Jan 16 '12 at 3:57
As @BrunoLeFloch suggests, add \listfiles before \documentclass and add everything after *File List* in your .log to your post. This will give us an indication of the package versions you're using. And, since xparse forms part of the l3packages - which is under development - it may be that your version is out of date. – Werner Jan 16 '12 at 6:02
you have the Debian 2009 TeXLive which is really old. Update the l3 packages – Herbert Jan 16 '12 at 8:35