# AMS align: Left aligned text/math plus multicolumn align

This question is basically a combination of two previous posts: Adding left aligned text to an equation. and AMS align / Align multiple “=”, too much space (the latter being my own question).

What I would need is a multicolumn align as discussed (and solved) in the second post linked above plus a left aligned label (text and/or math) as discussed in the first post. And if possible some indent for the left aligned text would be nice. So basically an itemized list with custom text / math instead of bullets and nicely aligned equations as items..

I tried

\begin{flalign}
&aaaa & bbb &= cccccc && = d\\
&ee & f &= g && = hh
\end{flalign}


and that gives me the left aligned labels and the other stuff aligned at the equal signs. But the third column is flushed all the way to the right. I guess that's the feature of flalign. Or am I doing something wrong here?

So: How can I get the desired format? Is there a way to combine flalign and alignat? Or are there other ways to do this? (I guess tables etc wouldn't really work here).

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I'm preeeetty sure all these "alignment environments" are \haligns under the hood (read: tables). –  morbusg Dec 6 '10 at 17:58
Related Question: Left-aligned text inside an equation. –  Peter Grill Jun 15 '12 at 17:30

It is a bit tricky ...

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

\noindent\hrulefill
\begin{flalign*}
\begin{aligned}
\rlap{aaaa}\\
\rlap{ee}
\end{aligned}
&&\arraycolsep=1.4pt
\begin{array}{rll}
bbb &= cccccc &= d\\[\jot]
f   &= g      &= hh
\end{array}
&&
\begin{aligned}
\refstepcounter{equation}(\theequation)\\
\refstepcounter{equation}(\theequation)
\end{aligned}
\end{flalign*}

\end{document}


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Not bad, but the horizontal alignment is not OK. I guess you need some struts. (And I think the OP really wants left aligned labels; this also comes out if you compile his code.) –  Hendrik Vogt Feb 4 '11 at 21:43
@Hendrik: thanks, the \jot was missing ... –  Herbert Feb 4 '11 at 21:52

Since alignat allows you to specify the spacing, what about:

\begin{alignat}
&ee & f &= g && = hh
\end{alignat}


Not perfect (the labels are not left flushed) but...

Another solution is to replace the normal equation numbering by your labels:

\begin{alignat}{2}
\tag*{aaaa}   bbb &= cccccc && = d\\
\tag*{ee}   f &= g && = hh
\end{alignat}


EDIT: note that the latest solution requires to pass the leqno option to the amsmath package...

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