# [Tex/LaTex] How to prevent a linebreak before align/equation environment in itemize?

alignitemizeline-breaking

The following code

\documentclass{article}
\usepackage{amsmath}
\begin{document}

\begin{itemize}
\item
\begin{align}
a&=b\\
&=d
\end{align}
\item
$$a=b\\ =d$$
\end{itemize}

\end{document}


produces

How to avoid the linebreak after the bullet and have the equations (1 and 3) begin on the same line (with the bullet)? I should perhaps emphasize that I want to preserve the numbering of the equations.

One can eliminate the \vspace*{-\baselineskip} from the other solution by using \abovedisplayskip=-\baselineskip instead. Note that equation uses \abovedisplayshortskip.

\documentclass{article}
\usepackage{amsmath}
\usepackage{showframe}
\begin{document}

\rule{1pt}{43\baselineskip}% force pagebreak

\begin{itemize}% changes below are local to this environment
\abovedisplayskip=-\baselineskip
\belowdisplayskip=0pt
\abovedisplayshortskip=-\baselineskip
\belowdisplayshortskip=0pt
\item\begin{align}
a&=b\\
&=d
\end{align}
\item$$a=b\\ =d$$
\end{itemize}

\end{document}