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I am trying to gain an understanding of the basics of elementary algebraic geometry and am reading Dummit and Foote Chapter 15: Commutative Rings and Algebraic Geometry ...
At present I am focused on Section 15.1 Noetherian Rings and Affine Algebraic Sets ... ...
I need someone to help me to fully understand the reasoning/analysis behind the statements in the Example on Page 661 of D&F regarding the coordinate ring of an affine algebraic set $$V \subseteq \mathbb{A}^n$$ ... ...
On page 661 (in Section 15.1) of D&F we find the following text and example (I am specifically focused on the Example):
https://www.physicsforums.com/attachments/4752
In the above text, in the Example, we find the following:
" ... ... In the quotient ring $$\mathbb{R} [V]$$ we have $$\overline{x} \overline{y} = 1$$ so $$\mathbb{R} [V] \cong \mathbb{R} [ x, 1/x ]$$. ... ... "
Could someone please explain rigorously and formally and, preferably in simple steps, exactly how/why $$\mathbb{R} [V] \cong \mathbb{R} [ x, 1/x ]$$ ... ... ?
Further, in the above text, D&F state " ... $$\overline{x} \overline{y} = 1$$ ... " ... ... BUT ... ... shouldn't this read " ... $$\overline{x} \overline{y} = \overline{1}$$ ... "
Hope someone can help with the above issues ...
Peter
At present I am focused on Section 15.1 Noetherian Rings and Affine Algebraic Sets ... ...
I need someone to help me to fully understand the reasoning/analysis behind the statements in the Example on Page 661 of D&F regarding the coordinate ring of an affine algebraic set $$V \subseteq \mathbb{A}^n$$ ... ...
On page 661 (in Section 15.1) of D&F we find the following text and example (I am specifically focused on the Example):
https://www.physicsforums.com/attachments/4752
In the above text, in the Example, we find the following:
" ... ... In the quotient ring $$\mathbb{R} [V]$$ we have $$\overline{x} \overline{y} = 1$$ so $$\mathbb{R} [V] \cong \mathbb{R} [ x, 1/x ]$$. ... ... "
Could someone please explain rigorously and formally and, preferably in simple steps, exactly how/why $$\mathbb{R} [V] \cong \mathbb{R} [ x, 1/x ]$$ ... ... ?
Further, in the above text, D&F state " ... $$\overline{x} \overline{y} = 1$$ ... " ... ... BUT ... ... shouldn't this read " ... $$\overline{x} \overline{y} = \overline{1}$$ ... "
Hope someone can help with the above issues ...
Peter