Es sei
M
⊆
N
{\displaystyle {}M\subseteq \mathbb {N} }
e
1
,
…
,
e
n
{\displaystyle {}e_{1},\ldots ,e_{n}}
N
n
→
M
{\displaystyle {}\mathbb {N} ^{n}\rightarrow M}
φ
:
K
[
X
1
,
…
,
X
n
]
→
K
[
M
]
{\displaystyle {}\varphi \colon K[X_{1},\ldots ,X_{n}]\rightarrow K[M]}
ker
φ
=
(
∏
i
∈
I
1
X
i
r
i
−
∏
i
∈
I
2
X
i
s
i
:
I
1
,
I
2
⊆
{
1
,
…
,
n
}
disjunkt
,
∑
i
∈
I
1
r
i
e
i
=
∑
i
∈
I
2
s
i
e
i
)
{\displaystyle \ker \varphi ={\left(\prod _{i\in I_{1}}X_{i}^{r_{i}}-\prod _{i\in I_{2}}X_{i}^{s_{i}}:\,I_{1},I_{2}\subseteq \{1,\ldots ,n\}{\text{ disjunkt }},\sum _{i\in I_{1}}r_{i}e_{i}=\sum _{i\in I_{2}}s_{i}e_{i}\right)}\,}
![{\displaystyle {}\varphi \colon K[X_{1},\ldots ,X_{n}]\rightarrow K[M]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/60028006d81138e2ab4ee543a101c783dec1358d)
