Recent content by cohomology

I've seen the notation \mathbb{Z}\left[\frac{1}{3}\right] and it should have something to do with localization. What does the notation mean?

I'm trying to understand direct limits so consider the direct limit \lim_\rightarrow (\mathbb{Z} \rightarrow \mathbb{Z} \rightarrow \mathbb{Z} \rightarrow \cdots) where each map is multiplication by 2. I concluded that the solution is \mathbb{Z}\sqcup\coprod(\mathbb{Z}-2\mathbb{Z}). Is this...