A while ago, I was searching for a TeX package which would provide a double integral symbol with a circle which I could use to typeset some lecture notes on surface integrals. I happened upon the esint package, which includes several integral symbols I had never seen before. In particular, integral symbols with a square (\sqint and \sqiint), a sloped dash (\fint) and the very curious \landupint and \landdownint. Is anyone familiar with any uses for these symbols?
Added (TB) Here's an image of the integral signs in question:
Best Answer
The one with the sloped dash is sometimes used to denote integral averages:
\fint_A $f(x)d\mu(x) = \frac{1}{\mu(A)} \int_{A} f(x) d\mu(x)$