# Left numbered equation inside list environment

I use the mathtools package with the leqno option in the memoir class. When inside a list environment, the equation label is misaligned.

\documentclass{memoir}

\usepackage[leqno]{mathtools}

\begin{document}
\begin{enumerate}
\item Inside list:
$$x=y.$$
\end{enumerate}

Outside list.
$$x\neq y.$$

\end{document}


Does anyone know a workaround to this? I've tried changing some list spacing lengths before the display environment but that did not work.

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I'm afraid it is a "feature" – egreg Jan 15 '13 at 18:52
interesting question. amsmath ordinarily sets the equation number flush left, even within a list, and many people have requested that it be aligned with the left margin of the list item text. this is the first time i've ever seen a request for the number to be moved to the "real" left margin. (i don't know how mathtools or memoir has changed this.) – barbara beeton Jan 15 '13 at 19:34

This is a "feature" of the standard classes; however the AMS classes offer a way out:

\documentclass{memoir}

\usepackage[leqno]{mathtools}

\newcommand\fullwidthdisplay{\displayindent0pt \displaywidth\columnwidth}
\AtBeginDocument{
\everydisplay\expandafter{\expandafter\fullwidthdisplay\the\everydisplay}
}
%%%

\begin{document}
\begin{enumerate}
\item Inside list:
$$x=y.$$
\end{enumerate}

Outside list.
$$x\neq y.$$

\end{document}


The equations will be centered to the line width, which is probably what you want.

However, the equation number will conflict with the item numbers; I prefer right equation numbers, in general, and particularly for these situations.

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Nice, it works well. I think now that the numbers on the right are indeed more aesthetically pleasing in this situation. However, I think that removing the display indent in the list environments gives a better look, even with numbers on the right, because of the equation alignment. – Dimas Jan 15 '13 at 21:32
@Dimas That's what the AMS classes do. Not everybody agrees. I simply try avoiding displayed equations in lists. :) Welcome to TeX.SX! (I forgot to say it in my first comment, sorry.) – egreg Jan 15 '13 at 21:38
Thanks! It's a very helpful community. – Dimas Jan 16 '13 at 16:10