[OS X TeX] Using align with "or"

[Ross Moore]

On 18/04/2011, at 11:39 AM, Alain Schremmer wrote:

>> Try  The LaTeX Companion    1st or 2nd editions.
> 
> But Companion two does not even mention \alignat. I just looked because I had been "doing it by hand", that is with a lot of \hspaces, and wanted to know if I had missed it.

You're right. It isn't in the 2nd edition, but is in the 1st.
(I had mine packed away to take to a LaTeX Workshop that I'm
giving today, so didn't check before replying.)


I'd guess that the reason it was dropped is because you don't actually
need the 'at' nor the number.
Try this:

\begin{align}
u      &=0 & \quad\text{or}\quad  && u+4    &=0  & \quad\text{or}\quad  && u-4    &=0 \\
u      &=0 &&&                       u      &=-4 &&&                       u      &=4 \\
\log x &=0 &&&                       \log x &=-4 &&&                       \log x &=4
\end{align}

The {align} environment counts the number of alignments actually
used. But their treatment is the same: alternating right/left.

> 
> Best regards
> --schremmer


Cheers,

	Ross

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Ross Moore                                       ross.moore at mq.edu.au 
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