I use TeXLive 2011.
I use ntheorem and multicol.
In a theorem environment, I want the theorem header to be separated from the body by a line break such that the multicols
-environment get's that and starts its second column at the same height as the first in the body.
This is roughly where the problem came from – in combination with a list from enumitem:
However – while writing the question, I noticed it can be cut down to the following minimal code:
\documentclass{scrreprt}
\usepackage{
ntheorem,
multicol,
}
\usepakage{lipsum}
\makeatletter
\newtheoremstyle{indentbreak}
{\item[##1]}
{\item[\rlap{\vbox{\hbox{##3}\hbox{\strut}}}]}
\makeatother
\theoremstyle{indentbreak}
%\theoremstyle{break}
\newtheorem{indentbreaktheorem}{Theorem}
\begin{document}
\begin{indentbreaktheorem}[Talking a lot and a lot and a lot and lot and a lot and a lot and a lot.]
\begin{multicols}{2}
\lipsum*[1]
\end{multicols}{2}
\end{indentbreaktheorem}
\end{document}
Which looks like this using the self-defined indentbreak environment:
The break environment yields a similar result (as above with the listings).
How can I define a theorem style such that this issue is resolved? I want to stay with ntheorem, but I am also interested in solutions for amsthm.