# Proper way to typset minimum value of variable in formula?

To typeset a value with a subscript I use this:

$U_{\text{res}}$


Which results in:

Now I'd like to write "the minimum value of Ures", how would I correctly typeset that?

The first thing I tried was

$U_{\text{res}_{\text{min}}}$


but that doesn't really look good. A coworker suggested

$U_{\text{res,min}}}$


but I'm also not sure if it's correct, and as part of a larger formula it seems to take up too much horizontal space:

-
Not really your question but it's better to use \mathrm than \text it's far more efficient and uses a fixed font, whereas text will pick up the current text font so would be italc in italic theorem texts – David Carlisle Apr 27 '13 at 18:01
I would highly recommend you use the letters "max" for maximum and reserve "min" for minimum. :-). An alternative to a subscript would be a function: $\mathrm{Max} (U_{res})$ – Peter Grill Apr 27 '13 at 18:13
Or, stick to the good old inequalities: say, $U_{\mathrm{trig}} \geqslant blahbah$. And, in the first of the equalities you display, you might consider using \left(\right) around the first term of the product, so that, the braces expand according the size of what goes inside them. – kan Apr 27 '13 at 18:18
@DavidCarlisle Interesting objection. Aside from efficiency, all the reasons you give are always advanced as arguments for \text (though admittedly, in contrast with \mbox). – Ryan Reich Apr 27 '13 at 19:15
@RyanReich if you are making a side condition or have some other text then \text is fine but here max is not a word it is essentially a math operator and should come from the math operator font to match \log or \sin etc and that will be the math roman font and not change depending on the outer text content. – David Carlisle Apr 27 '13 at 20:09

There is the operator $\min$ which might be appropriate here.
In order to define your own operators, consider using \DeclareMathOperator{\Minimum}{Minimum} from amsmath to be able to use $\Minimum U_\mathrm{res}$. Using the operator will give you suitable spacing around the operator, just as you have with i.e. \sin.
Why not just use \min – Aditya Apr 28 '13 at 8:21
Aditya, I somehow missed that. I corrected my answer accordingly. At least I it becomes clear to me again why I couldn't find a \min in my own math convenience package :) – AlexE Apr 28 '13 at 9:10