# How to make footnote for framed theorem appear at bottom of page?

I recently learned how to put a frame around display-math expressions, and now I'd like to add a footnote to the text in the frame. When I try this, however, the footnote appears at the bottom of the frame; I'd like it to appear at the bottom of the page. Also, the default footnote symbol is "a" in this case; I would like it to instead use numbers (starting from 1). How can I achieve these two things?

Here's a MWE:

\documentclass[12pt]{article}
\usepackage[a4paper,bindingoffset=0.2in,%
left=.5in,right=.5in,top=.5in,bottom=.5in,%
footskip=.25in]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{mathrsfs}
\usepackage{amssymb}
\usepackage[framemethod=TikZ]{mdframed}

\begin{document}

%\maketitle
\mdfdefinestyle{MyFrame}{%
linecolor=black,
outerlinewidth=0.25pt,
roundcorner=2pt,
innertopmargin=\baselineskip,
innerbottommargin=\baselineskip,
innerrightmargin=20pt,
innerleftmargin=20pt,
backgroundcolor=white}

\begin{mdframed}[style=MyFrame]
\textbf{Change of Variables Theorem (in $\mathbb{R}^3$):}
\footnote{Jerrold E. Marsden and Anthony J. Tromba. 2003.%
In Vector calculus. W.H. Freeman, 387.}
Let $D^*$ be an elementary region in $\mathbb{R}^3$, let
$\Phi(u,v,w) = (x(u,v,w),y(u,v,w),z(u,v,w))$ be a one-to-one
$C^1$ map from $D^*$ to $\mathbb{R}^3$, and let $D = \Phi(D^*)$.
Then
\begin{equation*}
\iiint\limits_{D} f(x,y,z) \, dx \,dy \, dz
= \iiint\limits_{D^*} f(x(u,v,w),y(u,v,w),z(u,v,w))
\left| \frac{\partial(x,y,z)}{\partial(u,v,w)} \right|
\, du \, dv \, dw.
\end{equation*}
\end{mdframed}

\end{document}


And here's what it currently displays:

• Just use \footnotemark in the mdframed environment, and \footnotetext{Jerrold E. Marsden and Anthony J. Tromba. 2003. In Vector calculus. W.H. Freeman, 387.}right after. Jun 26, 2021 at 17:25
• @Bernard: Thank you, that was a simple fix! Jun 26, 2021 at 17:59
• Simple fixes are always the best! Just a last remark: I suppose you have a bibliography. I wondered whether using \footcite from biblatex would work. Jun 26, 2021 at 18:16

The most evident way to adjust your code in order to get the desired result is the following:

\documentclass[12pt]{article}
\usepackage[a4paper,bindingoffset=0.2in,%
left=.5in,right=.5in,top=.5in,bottom=.5in,%
footskip=.25in]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{mathrsfs}
\usepackage{amssymb}
\usepackage[framemethod=TikZ]{mdframed}
\usepackage{footnote}

\begin{document}

%\maketitle
\mdfdefinestyle{MyFrame}{%
linecolor=black,
outerlinewidth=0.25pt,
roundcorner=2pt,
innertopmargin=\baselineskip,
innerbottommargin=\baselineskip,
innerrightmargin=20pt,
innerleftmargin=20pt,
backgroundcolor=white}
\savenotes
\begin{mdframed}[style=MyFrame]
\stepcounter{footnote}
\renewcommand{\thempfootnote}{\arabic{footnote}}
\textbf{Change of Variables Theorem (in $\mathbb{R}^3$):}\footnote{Jerrold E. Marsden and Anthony J. Tromba. 2003. In Vector calculus. W.H. Freeman, 387.} Let $D^*$ be an elementary region in $\mathbb{R}^3$, let $\Phi(u,v,w) = (x(u,v,w),y(u,v,w),z(u,v,w))$ be a one-to-one $C^1$ map from $D^*$ to $\mathbb{R}^3$, and let $D = \Phi(D^*)$. Then
\begin{equation*}
\iiint\limits_{D} f(x,y,z) \, dx \,dy \, dz = \iiint\limits_{D^*} f(x(u,v,w),y(u,v,w),z(u,v,w)) \left| \frac{\partial(x,y,z)}{\partial(u,v,w)} \right| \, du \, dv \, dw.
\end{equation*}
\end{mdframed}
\spewnotes

\end{document}


The result you will get is this:

• This does have the downside that the counter is incremented every time the environment is used. Dec 6 at 22:14