# [texhax] LaTeX amsmath: two equations aligned left-right

Olivier Cailloux olivier.cailloux at gmail.com
Mon Mar 28 11:20:44 CEST 2011

Le 28/03/2011 10:24, Lars Madsen a écrit :
> [snip]
>>>
>>> I would not write it like that at all (and I would never use
>>> multline, it often ends up looking really bad, especiellay if one
>>> afterwards change the margins)
>>>
>>> \documentclass[a4paper]{article}
>>> \usepackage[utf8]{inputenc}
>>> \usepackage{amssymb}
>>> \usepackage{amsmath}
>>> \usepackage{amsthm}
>>> \usepackage{empheq}
>>> \begin{document}
>>>
>>> \section{Now better}
>>> $\forall j \in J, a \in A, 1 \leq h \leq k-1 :$
>>> \begin{empheq}[left=\empheqlbrace]{align}
>>> &\frac{1}{M_j+ \delta_j} ((g_j(a) - g_j(b_h))+\delta_j)
>>> \leq C_j(a, b_h);\\
>>> &C_j(a,
>>> b_h) \leq \frac{1}{M_j} (g_j(a) - g_j(b_h)) + 1.
>>> \end{empheq}
>>> \end{document}
>>>
>>> The $\forall...$ is the premise (is that the correct word?) and I
>>> would not write that as a part of the equation it self, it is
>>> understood from the context that the equation is under those conditions
>> Thanks for your suggestion. It is simple and it answers the question.
>> Is it possible to get rid of empheq (that's yet an other package I
>> would have to learn)? I guess no...
>> Olivier
>
> No, empheq is so far the only package with enough flexibility to
> create a numbered construction like this.
>
> I would say that it and the mathtools package a good tools for your
> arsenal.
>
>
Ok I'll have a look. Mathtools (http://www.ctan.org/pkg/mathtools) seems
very interesting. Thanks again.
Olivier