# avoid eq. # on \shortintertext{} from mathtools

Does anyone know of an elegant way to avoid having to manually put an \nonumber at the end of \shortintertext{} when it is at the last line? As illustrated by the parts of the minimal working example (MWE) below that is commented out by a %.

I am very happy to use \shortintertext{} from mathtools. \shortintertext{} do not produce a equation number, which I like, but if I use \shortintertext{} as the last thing in an {align} equation block \shortintertext{} produces an extra equation number (as this, see blow for MWE)

It also seems as \shortintertext{} produces extra line spacing …

MWE (inspired by this SE example);

\documentclass[preview]{standalone}
\usepackage{mathtools}
\usepackage[usenames,dvipsnames]{xcolor}

\begin{document}
\begin{align}
\shortintertext{\color{gray}  We are trying to solve for $x$}
3+x &=4\\
\shortintertext{\color{gray} Subtract 3 from both sides:}
x &=4-3 \
\shortintertext{\color{gray} Hence, $x$ must be 1:}
x &=1
\shortintertext{\color{gray} Some comments on the conclussion} % \nonumber
\end{align} %  \vspace{-3.4 em}
\end{document}

• The first and last \shortintertext should be normal text outside align. – egreg Apr 1 '17 at 9:13
• @egreg, thank you for your feedback. I tried playing around with having my first and last comment outside align. However, there's a special line spacing for \shortintertext{} so that when I take comments outside align those comments do not have the same spacing as the rest of the equation comments. Maybe I shouldn't use \shortintertext{} at all. – Eric Fail Apr 1 '17 at 9:47

You can use a different approach:

\documentclass{article}
\usepackage{mathtools}
\usepackage[usenames,dvipsnames]{xcolor}

\newenvironment{compactequations}
{\setlength{\abovedisplayskip}{2pt plus 2pt}%
\setlength{\abovedisplayshortskip}{2pt plus 2pt}%
\setlength{\belowdisplayskip}{2pt plus 2pt}%
\setlength{\belowdisplayshortskip}{2pt plus 2pt}}
{}

\begin{document}

\begin{compactequations}
\noindent\textcolor{gray}{We are trying to solve for $x$}
\begin{align}
3+x &=4\\
\intertext{\color{gray} Subtract 3 from both sides:} % \nonumber
x &=4-3 \\
\intertext{\color{gray} Hence, $x$ must be 1:}
x &=1
\end{align}
\end{compactequations}

\end{document}


Without aligning at the equals signs:

\documentclass{article}
\usepackage{mathtools}

\newenvironment{compactequations}
{\setlength{\abovedisplayskip}{2pt plus 2pt}%
\setlength{\abovedisplayshortskip}{2pt plus 2pt}%
\setlength{\belowdisplayskip}{2pt plus 2pt}%
\setlength{\belowdisplayshortskip}{2pt plus 2pt}}
{}

\begin{document}

\begin{compactequations}
\noindent We are trying to solve for $x$
$$3+x=4$$
Subtract 3 from both sides:
$$x=4-3$$
Hence, $x$ must be 1:
$$x=1$$

• Thank you for taking the time to write up an elaborate answer. It does solve the issue, but it also adds quite a bit of code-customization to each align environment (and preamble). I've played around with having an  \nonumber after the last \shortintertext{}, inside my align environment, accompanied by an \vspace{-3.4 em} after the align environment, i.e. \end{align} \vspace{-3.4 em}. I've imagined a solution using a feature of mathtools I wasn't aware of or some other package that did the job with less customization. Your answer kinda give me a sense of the issue at hand. – Eric Fail Apr 1 '17 at 12:15