Meaning symbol $\overline{\lim_{n\rightarrow \infty}}$

Question

I found this symbol on a math book that I'm studying. It had never happened before. What does this mean?

$$\overline{\lim_{n\rightarrow \infty}}$$

Answer 1

It's another notation for $\limsup$. $\LaTeX$ has the command \varlimsup to produce it: $\varlimsup$. Similar is \varliminf producing $\varliminf$ for $\liminf$.