Affine ring
Definition
Let be a commutative unital ring. An affine ring over is a ring isomorphic to where is an ideal.
![{\displaystyle R[x_{1},x_{2},\ldots ,x_{n}]/I}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c1fd7ccd5121bfc230b1d1793df32ec8ca952c6b)
When we simply say affine ring, we may mean affine ring over a field, viz affine ring where the ring is a field.
Facts
An affine ring over an affine ring is also an affine ring over the base field.