The following codes return errors
\documentclass{article}
\begin{document}
cd\\
[asd]
\end{document}
But this one will work
\documentclass{article}
\begin{document}
cd
[asd]
\end{document}
The following codes return errors
\documentclass{article}
\begin{document}
cd\\
[asd]
\end{document}
But this one will work
\documentclass{article}
\begin{document}
cd
[asd]
\end{document}
[I think.\\can take an optional argument, which is a length. LaTeX picks up[asd]as an optional argument to\\, butasdis not a valid length, so you get an error. There have been similar questions before I think. – Torbjørn T. Apr 30 '14 at 14:33cd\\\relax [asd]. The\relaxwill prevent the following bracket from being taken as an argument. – Steven B. Segletes Apr 30 '14 at 14:37