Primfaktorzerlegung von 4 {\displaystyle 4} in Z [ i ] {\displaystyle \mathbb {Z} [i]} :
Wobei − 1 ∈ Z [ i ] × {\displaystyle -1\in \mathbb {Z} [i]^{\times }} und i + 1 {\displaystyle i+1} prim.
![{\displaystyle \mathbb {Z} [i]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/9ffa94e9e2e6d9e5e5373d5fafb954b902743fde)
![{\displaystyle -1\in \mathbb {Z} [i]^{\times }}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5292afa6fe52bc146f6cb3a8d07ab93d72ddc6e9)
