# Footnote to a footnote

How can I make a footnote to a footnote? E.g.,

Playfair's axiom\footnote{so called in honor of mathematician John Playfair, etc, etc., but was actually discovered by Proclus\footnote{Greek mathematician, etc, etc.}}

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Personal opinion: don't do this. –  Seamus Jul 15 '11 at 23:44
Well, I wouldn't do it for a formal and serious article, but it is not the case, and I think it's fun. –  Bruno Stonek Jul 15 '11 at 23:46
Some manual \footnotemark and \footnotetext trickery should do it, but like @Seamus I would do it. –  Martin Scharrer Jul 15 '11 at 23:46
Go ahead and do it and have fun. See "House of Leaves" for wonderfully nested footnotes and crazy text layout, and also a good story. –  mankoff Jul 16 '11 at 0:57
The package bigfoot does this (example given in the manual). It is not a normal need, but critical editions which themselves include a scholarly apparatus may make such a situation necessary. –  jon Nov 27 '11 at 4:32

Playfair's axiom\footnote{%
so called in honor of mathematician John Playfair, etc, etc.,
but was actually discovered by Proclus\footnotemark}
\footnotetext{Greek mathematician, etc, etc.}


But I'd advise against doing this.

As a bonus, here's an example of how you can really mess with footnotes.

\documentclass{article}
\begin{document}
\footnotetext[4]{We have to go back to the future, Marty!}
Foo\footnote{The footnote to this sentence is true\footnotemark}
\footnotetext{The footnote to this sentence is false\footnotemark[1]}
more body text\footnotetext[42]{This footnote doesn't appear in the main text}
And more body text\footnote{And we're back to the normal numbering.}
But look where this footnote text ends up!\footnotemark
\end{document}


A few points.

• The footnotes appear in the order the \footnotemarks appear in the text.
• Optional arguments to both \footnotemark and \footnotetext give you control over what number actually appears. (Useful for repeating a footnote if it is relevant again later.
• Everything here should work perfectly with \label and \ref
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The same trick allows you do get footnotes in minipages. And there it is more useful... –  Seamus Jul 15 '11 at 23:49
Perfect, I didn't know about these footnotemark and footnotetext commands. Thank you. I promise not to overuse it ;) –  Bruno Stonek Jul 15 '11 at 23:51
I'm not a big fan of footnotes in general. If it's important enough to mention, it's important enough for the main text. Rule of thumb: never have more footnotes than pages. But that's just me... –  Seamus Jul 15 '11 at 23:53
Here is more information on \footnotemark[<num>] and \footnotetext[<num>]{<text>}, since it actually allows overriding of the mark used in the footnote. –  Werner Jul 15 '11 at 23:54
@Werner thanks for that! I'll update my answer into a proper "here's how footnotes work" answer tomorrow. (it's 1am here) –  Seamus Jul 15 '11 at 23:59

Use the bigfoot package (as I suggested in the above comment). E.g.:

\documentclass{article}

\usepackage{bigfoot}
\DeclareNewFootnote{Default}
\DeclareNewFootnote{B}[alph]
\MakeSortedPerPage{B}% perhaps also useful to know about

\begin{document}

\verb+bigfoot+%
\footnote{Available on CTAN.} %
improves \LaTeX's%
\footnoteB{Widely known to be less than ideal.} %
footnoting abilities.  \verb+bigfoot+%
\footnote{Available on CTAN.} %
improves \LaTeX's%
here: one important limitation is that Higher-placed footnotes