Ring theory MOC GCD Let be an integral domain and . An element is a greatest common divisor or GCD of and iff ring and implies .1 The GCD is unique up to associate elements, leading to the abuse of notation Properties GCDs exist for nonzero elements in a UFD develop | en | sembr Footnotes 2009. Algebra: Chapter 0, §V.2.1, p. 252 ↩