Defining a new command to insert Quine Corners

Question

How do I define a new command that will surround given text with Quine corners?

I'm looking for something that will take me from:

$\qquote{Ixy}$ %Where "\qquote" is the name of the new command

to

$\ulcorner Ixy \urcorner$

Answer 1

\documentclass{article}
\usepackage{amsmath,amssymb}

\newcommand\qquote[1]{\ulcorner#1\urcorner}

\begin{document}

$\qquote{lxy}$

\end{document}

Notice that I didn't use $...$ in the definition to avoid possible errors when trying to write the command inside another math-mode expression such as in $a=\qquote{b}$, for example. Some people would then opt for a definition using \ensuremath:

\newcommand\qquote[1]{\ensuremath{\ulcorner#1\urcorner}}

so you can use \qquote both in math and text modes. I personally prefer not to use \ensuremath and to "force" the use of \qquote only in math-mode.