This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Arch Linux) (format=pdflatex 2013.10.17)  23 OCT 2013 14:53
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**intro.tex
(./intro.tex
LaTeX2e <2011/06/27>
Babel <3.9f> and hyphenation patterns for 78 languages loaded.
! Undefined control sequence.
l.2 \section
            {Introduction}\label{sec:introduction}
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l.2 \section
            {Introduction}\label{sec:introduction}
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!  ==> Fatal error occurred, no output PDF file produced!