How do I post in latex the subtext under some formulas.

For example

http://www.m-hikari.com/ija/forth/dr...JA5-8-2009.pdf

Go to page 233 of this document and there are formulas with

"max" for example, and under the "max" there is subtext.

Just look at the $\displaystyle ||A||_{1\infty}$ norm and you see that there are conditions under the "max" to the effect of $\displaystyle (i,j)|\in......$.

How do I put this under the $\displaystyle max$?

regards

Bucephalus