Ring theory MOC

GCD

Let ๐‘… be an integral domain and ๐‘Ž,๐‘ โˆˆ๐‘…. An element ๐‘‘ โˆˆ๐‘… is a greatest common divisor or GCD of ๐‘Ž and ๐‘ iff #m/def/ring

โŸจ๐‘Ž,๐‘โŸฉโŠดโŸจ๐‘‘โŸฉ

and โŸจ๐‘Ž,๐‘โŸฉ โŠดโŸจ๐‘‘โ€ฒโŸฉ โŠดโŸจ๐‘‘โŸฉ implies โŸจ๐‘‘โ€ฒโŸฉ =โŸจ๐‘‘โŸฉ.1 The GCD is unique up to associate elements, leading to the abuse of notation

gcd{๐‘Ž,๐‘}=๐‘‘.

Properties

  1. GCDs exist for nonzero elements in a UFD


#state/develop | #lang/en | #SemBr

Footnotes

  1. 2009. Algebra: Chapter 0, ยงV.2.1, p. 252 โ†ฉ