Add {multiline} to DEFAULTENV

[pauloney]

{multline} of the package amsmath should be added to the list of environments to be ignored as per example:

\documentclass{report}
\begin{document}

\begin{multline}
z_{n+2}+pz_{n+1}+qz_n=(y_{n+2}+py_{n+1}+qy_n)-\\
-C_1r^n(r^2+pr+q)-C_2nr^n(r^2+pr+q)-C_2r^nr(2r+p).
\end{multline}

\end{document}

[pauloney]

Also add {cases} too, as per examples below:

\documentclass{report}
\begin{document}

\begin{cases}
2s - 0 \le s \le 1/2\\
\end{cases}

\end{document}