localization
Let be a commutative ring and let be a nonempty multiplicative subset of . The localization of at is the ring whose elements are equivalence classes
of under the equivalence relation if for some . Addition
and multiplication in are defined by:
- •
- •
The equivalence class of in is usually denoted . For , the localization of at the minimal multiplicative set containing is written as . When is the complement
of a prime ideal
in , the localization of at is written .