Quotations in math mode using \enquote command from csquotes package

I'm using the \enquote command from the csquotes package for setting quotes.

When I invoke quotations inside math mode,
either by hand

<some math>''


or by enquote

\enquote{<some math>}


it renders differently than in text mode.

Here's an example:

Can someone explain why this behavior occurs?

For adjusting the quotation marks by hand, I found this workaround by egreg.

How can I adjust the quotation marks invoked by enquote in math mode?

Here's a MWE, the one from above:

\documentclass[preview]{standalone}
\usepackage{csquotes}
\begin{document}
In text mode:\\
Quote by hand: Blub''\\
Quote by enquote: \enquote{Blub}

In math mode:\\
Quote by hand: $a^2+b^2=c^2''$\\
Quote by enquote: $\enquote{a^2+b^2=c^2}$
\end{document}

• \enquote{$formula$} rather than $\enquote{formula}$, unless your quotes are part of the math. Are they? – egreg Dec 12 '18 at 17:29
• Problem is I have it as something like $\ldots \enquote{\ldots} \ldots$. Do you have an idea what to do? – C-Star-W-Star Dec 12 '18 at 17:30

LaTeX issues one error and two warnings:

! Double superscript.

l.13 Quote by hand: $a^2+b^2=c^2' '$
?

LaTeX Warning: Command \textquotedblleft invalid in math mode on input line 15.

LaTeX Warning: Command \textquotedblright invalid in math mode on input line 15


Such errors and warnings should not be disregarded; it's a perhaps sad truth that \textquotedblleft in math mode produces a backslash, whereas \textquotedblright actually produces a closing double quote.

The error is because ' in math mode is interpreted as ^{\prime}, so c^2' indeed has a double superscript (the converse c'^2 is instead legal, as is c''^2).

If you want to quote something in math mode, you should use math symbols.

\documentclass{article}

\DeclareMathSymbol{\mlq}{\mathord}{operators}{'134}
\DeclareMathSymbol{\mrq}{\mathord}{operators}{'42}

\begin{document}

$\dots\mlq\dots\mrq\dots$

\end{document}


• Wow, true that, it issues those warnings, completely didn't notice them, thanks! (Have it running in command prompt as -interaction=batchmode with -file-line-error only and checking for warnings only on an ad-hoc basis.) – C-Star-W-Star Dec 12 '18 at 17:48
• Thanks, the integration worked perfectly with your solution and defining \newcommand{\mathenquote}[1]{\mlq #1\mrq}. Thanks a lot!! – C-Star-W-Star Dec 12 '18 at 17:57

You have answered yourself: the quotes should be in the text mode:

\documentclass[preview]{standalone}
\usepackage{csquotes}
\begin{document}
In text mode:\\
Quote by hand: Blub''\\
Quote by enquote: \enquote{Blub}

In math mode:\\
%Quote by hand: $a^2+b^2=c^2''$\\
Quote by hand: $a^2+b^2=c^2$''\\

%Quote by enquote: $\enquote{a^2+b^2=c^2}$
Quote by enquote: \enquote{$a^2+b^2=c^2$}
\end{document}


• Problem is that I need it as something like $\ldots \enquote{\ldots} \ldots$. Do you have an idea what to do? – C-Star-W-Star Dec 12 '18 at 17:33
• \ldots work(s) also in the text mode. So \ldots \enquote{\ldots} \ldots will work. – Przemysław Scherwentke Dec 12 '18 at 17:34
• Sorry, should have written $<some formulas> \enquote{<formula>} <more formulas>$ and under different circumstances like labels in tikzcd and other situations. – C-Star-W-Star Dec 12 '18 at 17:37
• If you use amsmath, you have a simple construction \text\enquote{$...$}}. – Przemysław Scherwentke Dec 12 '18 at 17:40
• Do you think i can/is it good idea for me to redefine simply then \enquote as something like \ensuretextmode\enquote? – C-Star-W-Star Dec 12 '18 at 17:41