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

Mon Mar 28 10:24:13 CEST 2011

[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.

--

/daleif