My book describes the polynomial ring $R[X]$ as: $R[X] = R[\mathbb{N}] = \{f: \mathbb{N} \rightarrow R | \hspace{ 2mm} f(n) = 0, n \gg 0\}$. What is exactly meant by this?
What do the double arrows mean $(\gg)$? The author is a Danish mathematician and the book is designed for a first semester algebra course.