What's the right way to typeset the phrase "x-y plane" in US English? A full sentence example would be something like:
Our new detector has incredible resolution in the x-y plane, but provides no position information in the z direction.
A few options I can think of are:
$x-y$ plane $x$-$y$ plane $x$ - $y$ plane $x$--$y$ plane $x$ -- $y$ plane