Roughly speaking - as in the introductory definition of the Riemann integral - we have a whole notation and apparatus for dealing with an infinite sum of ever smaller 'widths' becoming the integral - viz., the integral of a function over [0,q]:
$$\lim_{n\to \infty}\sum_{w=0}^\frac{q}{n} f(w)\cdot \frac{1}{n}=\int_0^qf(w) dw$$
Is there an equivalent symbol and theory around what would look like:
$$\lim_{n\to \infty}\prod(1+\frac{r}{n})^\frac{1}{n}=???? $$
The obvious place this would come up would be in finance, moving from discrete compounding to continuous time compounding. The answer is $e^r$, but I have never seen, nor know of, a general notation or methodology for the right hand side that looks like an integral.