1

I want to have two equation counter format for normal equations in text and in footnote as follows:

enter image description here

I think best way is to redefine footnote equations, but I don't know how do it. Any help would be greatly appreciated.

Thanks.

  • 1
    Please give a use case for wanting to assign a number to a displayed equation in a footnote. – Mico Feb 15 '17 at 13:51
  • \footnote is no environment and is this really useful, to hide 'important' equations in footnotes? – user31729 Feb 15 '17 at 13:52
  • for example F.thesection – C.F.G Feb 15 '17 at 13:54
3

I doubt the usefulness of a specific counter for equations in a footnote (or numbered equations in a footnote at all), but here's a quick hack, by hijacking the \footnote code and temporarily setting the \c@equation and \theequation macros to \c@footequation and \thefootequation, in a group.

\documentclass{article}

\usepackage{amsmath}

\usepackage{letltxmacro}

\usepackage{xparse}

\newcounter{footequation}[section]

\renewcommand{\thefootequation}{F.\arabic{footequation}}
\makeatletter
\LetLtxMacro\latex@@footnote\footnote
\RenewDocumentCommand{\footnote}{om}{%
  \begingroup
  \let\c@equation\c@footequation
  \let\theequation\thefootequation
  \IfValueTF{#1}{%
    \latex@@footnote[#1]{#2}%
  }{%
    \latex@@footnote{#2}%
  }%
  \endgroup
}
\makeatother


\begin{document}
\begin{equation}
  E=mc^{2} \label{foo}
\end{equation} 

See \eqref{footeq}

Some text\footnote{\begin{equation}E=mc^{2}\label{footeq}\end{equation}}

\begin{equation}
  c^{2}=a^{2} + b^{2} \label{pythagoras}
\end{equation} 

Some text\footnote{\begin{equation} c^{2}=a^{2} + b^{2}\label{footpythagoras}\end{equation}}

\end{document}

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.