AMS align: left aligned text/math plus multicolumn alignment

Question

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

What I 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).

I'm preeeetty sure all these "alignment environments" are \haligns under the hood (read: tables). — morbusg, Dec 06 '10 at 17:58

score 1 · Answer 1 · edited Jun 03 '17 at 07:05

1

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}

enter image description here

edited Jun 03 '17 at 07:05

CarLaTeX

62,716

answered Feb 04 '11 at 20:26

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 04 '11 at 21:43
@Hendrik: thanks, the \jot was missing ... – Feb 04 '11 at 21:52

score 0 · Answer 2 · edited Jul 14 '17 at 15:09

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

\begin{alignat}
 &aaaa \qquad\qquad& bbb &= cccccc && = d\\
 &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...

AMS align: left aligned text/math plus multicolumn alignment

2 Answers2

Linked