# How can I get aligned equations not to be spoiled by an item?

Is it possible to use itemize between align? For instance one wants to list some equations with previous explanations following an item, but one wants the explanations not to break the align structure, so that, say, the equal signs are aligned? What I want is:

My attempts to interlace an item in an give an error.

In this MWE:

\documentclass{standalone}
\usepackage{amsmath}
\begin{document}
\begin{itemize}
\item This is the expansion for $f$:
\begin{align}
f(X) = & \sum_n {t_n+x_n-s_n-2} X^n
\end{align}
\item This is the expansion for $g$:
\begin{align}
g(X) = & \sum_m {r_m} X^m
\end{align}
\end{itemize}
\end{document}


I get the equations unaligned.

• There's no need for the two equal signs to be aligned in this case. Just use equation. – egreg Aug 12 '14 at 9:04
• btw, you should use &= instead of =& in align constructions. – yo' Aug 12 '14 at 12:39

Use the \intertext command foralign for any text you wish to have between aligned equations. i.e. your MWE would become:

\documentclass{standalone}
\usepackage{amsmath}
\begin{document}
\begin{itemize}
\item This is the expansion for $f$:
\begin{align}
f(X) &= \sum_n {t_n+x_n-s_n-2} X^n
\intertext{\item This is the expansion for $g$:}
g(X) &= \sum_m {r_m} X^m
\end{align}
\end{itemize}
\end{document}


As mentioned by @tohecz it is conventional to use &= not =&

• Please, correct for the OP the position of &: the proper way is &= rather than =&. – yo' Aug 12 '14 at 12:38
• @TomBrien -- the reason for the relative positions of &= is stronger than mere convention: if the & is put after the operator, the spacing is wrong. – barbara beeton Aug 13 '14 at 12:22
• @barbarabeeton just tested this and your right. I've always done it the 'correct' way so never noticed. – Tom Brien Aug 13 '14 at 12:33