I was reading this paper where I came across a function with a weird double summation notation. The function roughly looks like this,
$$2\sum_{x = 1}^{11}(30-x)\sum_{t = 1}^{x-1} t^2$$
My question is, what will be the value of inner summation when $x = 1$? My best guess was, when $x = 1$, $x-1$ is not defined in the series. Thus the answer will be $0$ when $x = 1$.
Any help will be appreciated, Thanks.