How can I use quotation marks like brackets in math mode?

Question

I'd like to enclose some content in quotation marks in math mode. The content is text, so I put it as a parameter to \text from amsmath.

S = \text{“some text”}

But the quotation marks aren't part of the content of S, so I'd like to not include them in the \text tag. Ideally, the quotation marks would function as delimiters like brackets, so it would be this:

S = \left“ \text{some text} \right”

That would allow also parity checks, using them with things other than text, and maybe automatic sizing and positioning.

How can I do something like that? I mean defining custom bracket-like delimiters or an other tool for setting text strings in math mode.

Answer 1

New Solution

I defined a command \mathquote{...} that inserts quotation marks depending on the vertical size of its content.

Code

\documentclass{article}

\usepackage{amsmath}

\newlength{\mqheight}
\newlength{\mqnormalheight}
\settoheight{\mqnormalheight}{\hbox{gM}}%
\newcommand{\mathquote}[1]{%
    \settoheight{\mqheight}{\hbox{\ensuremath{#1}}}%
    \addtolength{\mqheight}{-\mqnormalheight}%
    \text{\raisebox{\the\mqheight}{``}}%
    #1%
    \text{\raisebox{\the\mqheight}{''}}%
    %\qquad\text{(raise quotes by: \the\mqheight)}% (info)
}

\begin{document}

\begin{align}
    a &= \mathquote{\sum\limits_{i=1}^N i}\\
    b &= \mathquote{\int\limits_{a}^{b} x^2 dx}\\
    c &= \mathquote{\left(\sum\limits_{i=1}^n i\right) + x}\\
    d &= \mathquote{g + B}
\end{align}

\end{document}

Result

Old Solution

Your question is not completely clear to me, but to get automatic parity check you can use the package csquotes and its command \enquote{...}, which is also useful for normal text and different languages.

In this case (language = default = english) the result is the same as typing “ and ”.

Code

\documentclass{article}

\usepackage{amsmath}
\usepackage{csquotes}

\begin{document}

\begin{align}
    a &= \text{“some text”}\\
    b &= \text{\enquote{some text}}
\end{align}

\end{document}

Result