# Defining a command for amsmath's align environment

I'd like to define a shorthand command for \begin{align*} and \end{align*}. When I write

\newcommand{\ba}{\begin{align*}}


it works fine. But when I write

\newcommand{\ea}{\end{align*}}


LaTeX complains. It looks like it's interpreting it as part of the environment and is not happy with that. Anyone know how to fix this?

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## migrated from stackoverflow.comMar 9 '11 at 12:47

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This seems the sort of thing you should have a shortcut for in your editor, rather than in LaTeX itself. – ShreevatsaR Apr 21 '10 at 14:27

An alternative solution -- this is the code in the custom document class I use for everything:

\newcommand{\eq}[1]{\begin{align*}#1\end{align*}}


Usage:

\eq{
x^2 + 9 &= 0
}


(Obviously, change the command name to suit your preference.)

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Thanks for the help! I defined the \eq command, and it's working well. – Dmitry Vaintrob Apr 30 '10 at 6:01
This is a great idea, thank you. What does the [1] signify? – Eric Auld Sep 26 '13 at 15:52
It's the number of arguments your new \eq command will require. See en.wikibooks.org/wiki/LaTeX/Macros for more information. – Etaoin Sep 28 '13 at 0:03

A little testing shows that this appears to be fairly specific to the "align" environment from amsmath. For example,

\documentclass{article}

\usepackage{amsmath}

\newcommand{\bc}{\begin{center}}
\newcommand{\ec}{\end{center}}

\begin{document}

\bc
hello world
\ec

\end{document}


works fine. I'm not sure why align* doesn't work (it doesn't work without the star either); I suspect that the myriad expansions and aliases surrounding the align environment do something a little more complicated than a "traditional" LaTeX environment. However, I have found something that might just achieve the same objective for you:

\documentclass{article}

\usepackage{amsmath}


\begin{document}

\ba
x^2 &= y^2 \\
z^2 &= t^2
\ea

\end{document}


Hope that helps!

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It seems to me that it's a bug.

\newcommand{\ba}{\begin{align}}
\newcommand{\ea}{\end{align}}
\ba
x=1
\ea


LaTeX complains about align not being closed.

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This is not a bug, but indeed unexpected behaviour of align. It's explained over at tex.stackexchange.com – Hendrik Vogt Nov 18 '10 at 16:21