# ntheorem: extra space between a proof and a theorem

In ntheorem, when I have a proof that ends with a displayed equation that is immediately followed by a theorem, I seem to get too much space between the equation and the theorem.

In my example, I assume the space around the first displayed equation should match the space around the second, but there is excessive space under the first displayed equation. Can anything be done other than adding a negative \vspace command after the first displayed equation?

\documentclass{article}

\usepackage[leqno]{amsmath}
\usepackage[standard,amsmath,thmmarks]{ntheorem}

\begin{document}

\begin{proof}
Text.
\begin{gather}
1+1=2.
\end{gather}
\end{proof}

\begin{theorem}
Text (automatic theorem).
\end{theorem}

\begin{proof}
Text.
\begin{gather}
1+1=2.
\end{gather}
\end{proof}

\noindent
\textbf{Theorem 1}
\emph{Text (manual theorem).}

\end{document}


To remove the extra space, you may try

\documentclass{article}

\usepackage[leqno]{amsmath}
\usepackage[standard,amsmath,thmmarks]{ntheorem}

\theorempreskip{0pt}
\renewtheorem{theorem}{Theorem}

\begin{document}

\begin{proof}
Text.
\begin{gather}
1+1=2.
\end{gather}
\end{proof}

\begin{theorem}
Text (automatic theorem).
\end{theorem}

\begin{proof}
Text.
\begin{gather}
1+1=2.
\end{gather}
\end{proof}

\noindent
\textbf{Theorem 1}
\emph{Text (manual theorem).}

\end{document}

• I was actually wondering if this is an ntheorem bug and if there was a known way to fix it. – MSC Jan 29 '16 at 13:01
• But it does seem that under the first displayed equation, I'm getting one below-displayed-math space plus one above/below-theorem space. In other words, it seems that ntheorem is removing the space after the proof but leaving the space before the theorem, when it should also be removing the space before the theorem. – MSC Jan 29 '16 at 13:16
• In ntheorem, isn't the theorem skips shared, that is one cannot make individual skips for the various theorem constructions – daleif Aug 26 '16 at 4:53