# Is it possible to include text within empheq

Right now, I have

\begin{gather}
Eq1
\\ Eq2
\\ Eq3
\end{gather}

where variables ... are defined as

\begin{gather}
Eq4
\\ Eq5
\end{gather}


I would like to put a box around all of this including the text "where variables ... are defined as". Is it possible to do this using the empheq environment?

Yes, it's possible, and you have several options depending on the desired result. Below I show six different possibilities.

The code:

\documentclass{article}
\usepackage[vmargin=1cm]{geometry}
\usepackage{amsmath}
\usepackage[many]{tcolorbox}
\usepackage{empheq}

\begin{document}

\begin{empheq}[box=\fbox]{gather}
Eq1
\\ Eq2
\\ Eq3
\\ \notag\text{where variables ... are defined as}
\\ Eq4
\\ Eq5
\end{empheq}

\begin{empheq}[box=\fbox]{gather}
Eq1
\\ Eq2
\\ Eq3
\\ \notag\text{\parbox{.7\linewidth}{where variables ... are defined as}}
\\ Eq4
\\ Eq5
\end{empheq}

\begin{empheq}[box=\tcbhighmath]{gather}
Eq1
\\ Eq2
\\ Eq3
\\ \notag\text{where variables ... are defined as}
\\ Eq4
\\ Eq5
\end{empheq}

\begin{empheq}[box=\tcbhighmath]{gather}
Eq1
\\ Eq2
\\ Eq3
\\ \notag\text{\parbox{.7\linewidth}{where variables ... are defined as}}
\\ Eq4
\\ Eq5
\end{empheq}

\begin{tcolorbox}[enhanced,oversize,breakable,colframe=cyan,colback=cyan!20,top=-\abovedisplayskip,bottom=0pt]
\begin{gather}
Eq1
\\ Eq2
\\ Eq3
\end{gather}
where variables ... are defined as
\begin{gather}
Eq4
\\ Eq5
\end{gather}
\end{tcolorbox}

\noindent\makebox[\linewidth]{\fcolorbox{orange}{orange!10}{%
\begin{minipage}[t]{\linewidth}
\vskip-\abovedisplayskip
\begin{gather}
Eq1
\\ Eq2
\\ Eq3
\end{gather}
where variables ... are defined as
\begin{gather}
Eq4
\\ Eq5
\end{gather}
\end{minipage}}}

\end{document}


## Explanation

• In options one through four, instead of two gather environments I used just one. The text was written using \text.

• In options two and four, the text was additionally placed inside a \parbox, so you can control its width and have possible line breaks.

• Options one and two use a standard empheq environment with \fbox as the framing method.

• Options three and four use the interaction between tcolorbox and empheq; the framing method is \tcbhighmath.

• In option five, a tcolorbox was used to surround both gather environments and the text; page breaks are allowed.

• In option six, a \fcolorbox was used to surround both gather environments and the text; page breaks are not allowed since a minipage was used.

• Thanks for your quick and helpful response. With tcolorbox, is there a way to change the width of the frame? – KevinB Jul 25 '15 at 17:43
• @KevinB You're welcome. I edited my answer (in case you didn't noticed it). Regarding your question, you can use boxrule as in \begin{tcolorbox}[oversize,breakable,colframe=cyan,colback=cyan!20,boxrule=0.4pt] ...\end{tcolorbox} (change 0.4pt to the desired value.) – Gonzalo Medina Jul 25 '15 at 17:47
• I did see your edit. Thanks for such a thorough answer with the different options. I like the tcolorbox option the best. However when I use boxrule: \begin{tcolorbox}[oversize,breakable,colframe=black,colback=white!20,boxrule=0.4 p‌​t] I'm getting an error " Illegal unit of measure (pt inserted). <to be read again> p l.351 ...ck,colback=white!20,boxrule=0.4 p‌​t] Dimensions can be in units of em, ex, in, pt, pc, cm, mm, dd, cc, nd, nc, bp, or sp; but yours is a new one!" – KevinB Jul 25 '15 at 17:53
• @KevinB for some reason there's a strange character in your code in the pt part (probably a result of copy-paste). Delete 0.4 pt and write it again directly from your keyboard. – Gonzalo Medina Jul 25 '15 at 18:04
• Thanks, that works. Unfortunately with tcolorbox, the equations I want to box are getting split into two boxes because they extend beyond the bottom of the page. Therefore, I think I will use fcolorbox because as you mentioned, that doesn't allow page breaks. With fcolorbox, how should I specify the frame width? Thanks for all your help. – KevinB Jul 25 '15 at 18:28