# Commentary for "Difference equation tutorial: draft of part I"

#### MarkFL

Hey Carlo , In this post , you are saying that $$\displaystyle \displaystyle \lim_{n \rightarrow \infty} a_{n}=a_{0}+\lim_{n \rightarrow \infty} \sum_{k=0}^{n-1} \Delta_{k}$$ , this is a general formula for testing the convergence any $$\displaystyle a_n$$ ,right ?