# Reduce vertical equation space in enumeration

In the example:

\documentclass[12pt,a4paper]{article}
\usepackage[fleqn]{amsmath}
\usepackage{enumitem}

\begin{document}
\begin{enumerate}[label=(\roman*)]
\item $N_H(P)$ is a subgroup of G
\item $N_H(P) \cap P \Delta N_H(P)$
\item
\begin{equation*}
{\setlength{\mathindent}{0cm}
\frac{N_H(P) P}{P} \cong \frac{N_H(P)}{ N_H(P) \cap P}
}
\end{equation*}
\end{enumerate}

\end{document}


The last item has too much vertical space, how to remove it? I've tried various combinations of gather, abovedisplayskip etc. If there is a better way to do this I'd appreciate that. The block is standalone free text, not in any theorem etc.

As you are in a list I would do as you did for the first two and use inline math.

\documentclass[12pt,a4paper]{article}
\usepackage[fleqn]{amsmath}
\usepackage{enumitem}

\begin{document}
\begin{enumerate}[label=(\roman*)]
\item $\displaystyle N_H(P)$ is a subgroup of $\displaystyle G$
\item $\displaystyle N_H(P) \cap P \Delta N_H(P)$
\item $\displaystyle \frac{N_H(P) P}{P} \cong \frac{N_H(P)}{ N_H(P) \cap P}$
\end{enumerate}

\end{document}