How is math mode processed in TeX? Is typing \n (in editor) in math mode equivalent to one space? I am asking, because I struggled to find a bug in source code (between a lot of matrices :-) ), and the reason was following:
\documentclass{article}
\begin{document}
$1
2$
\end{document}
compiles,
\documentclass{article}
\begin{document}
$1
2$
\end{document}
but this does not. (missing $ error)
I know that I can add % between to maintain source code style, but the question is about why above error happens.
