I’m using ntheorem
to set my proofs, using the nonumberbreak
style:
\documentclass{article}
\usepackage{amsmath}
\usepackage[amsmath]{ntheorem}
\theoremstyle{nonumberbreak}
\newtheorem{proof}{Proof}
So if I write
\begin{proof}
One line
\begin{align*}
\text{One equation}
\end{align*}
\end{proof}
I get the desired output (left one in the picture below).
But in some cases, my proof starts with some math environment right away, e.g.
\begin{proof}
\begin{align*}
\text{One equation}
\end{align*}
\end{proof}
In this case, I get exactly the same spacing as before, as if I replaced “One line” by ~
or something like that.
I can reduce the vertical space by setting \abovedisplayskip
to 0px
(third picture below), but there is still precisely one line left.
How can I get rid of this line?
\setlength{\abovedisplayskip}{-\baselineskip}
yields the desired result, but is of course only a hack and will break horribly if there are multiple math environments in the proof.