Let ๐ be an integral domain and ๐,๐โ๐ .
An element ๐โ๐ is a greatest common divisor or GCD of ๐ and ๐ iff #m/def/ring
โจ๐,๐โฉโดโจ๐โฉ
and โจ๐,๐โฉโดโจ๐โฒโฉโดโจ๐โฉ implies โจ๐โฒโฉ=โจ๐โฉ.1
The GCD is unique up to associate elements, leading to the abuse of notation