Is it true that the generators of a commutative ring is finite?












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So I am thinking about the structure of a commutative ring $R$. Give a family of principal ideals $A={(x_{i})}$, and if $R=bigcup_{i}(x_{i})$, is it true that there are finite number of principal ideals in $A$ such that $(1)=(x_{1},x_{2},...,x_{n})$? Actually, this comes from the statement that "Affine schemes are quasi-compact". Can anyone help? Thanks!










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  • $begingroup$
    Are you sure you mean $cup_i(x_i)$, and not the ideal generated by the union (equivalently, by elements $x_i$? In both cases the statement is true, but from the given context I presume you mean the latter.
    $endgroup$
    – Wojowu
    Jan 25 at 9:34
















0












$begingroup$


So I am thinking about the structure of a commutative ring $R$. Give a family of principal ideals $A={(x_{i})}$, and if $R=bigcup_{i}(x_{i})$, is it true that there are finite number of principal ideals in $A$ such that $(1)=(x_{1},x_{2},...,x_{n})$? Actually, this comes from the statement that "Affine schemes are quasi-compact". Can anyone help? Thanks!










share|cite|improve this question











$endgroup$












  • $begingroup$
    Are you sure you mean $cup_i(x_i)$, and not the ideal generated by the union (equivalently, by elements $x_i$? In both cases the statement is true, but from the given context I presume you mean the latter.
    $endgroup$
    – Wojowu
    Jan 25 at 9:34














0












0








0





$begingroup$


So I am thinking about the structure of a commutative ring $R$. Give a family of principal ideals $A={(x_{i})}$, and if $R=bigcup_{i}(x_{i})$, is it true that there are finite number of principal ideals in $A$ such that $(1)=(x_{1},x_{2},...,x_{n})$? Actually, this comes from the statement that "Affine schemes are quasi-compact". Can anyone help? Thanks!










share|cite|improve this question











$endgroup$




So I am thinking about the structure of a commutative ring $R$. Give a family of principal ideals $A={(x_{i})}$, and if $R=bigcup_{i}(x_{i})$, is it true that there are finite number of principal ideals in $A$ such that $(1)=(x_{1},x_{2},...,x_{n})$? Actually, this comes from the statement that "Affine schemes are quasi-compact". Can anyone help? Thanks!







abstract-algebra ideals






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edited Jan 25 at 10:26









user26857

39.4k124183




39.4k124183










asked Jan 25 at 9:09









Yuyi ZhangYuyi Zhang

15117




15117












  • $begingroup$
    Are you sure you mean $cup_i(x_i)$, and not the ideal generated by the union (equivalently, by elements $x_i$? In both cases the statement is true, but from the given context I presume you mean the latter.
    $endgroup$
    – Wojowu
    Jan 25 at 9:34


















  • $begingroup$
    Are you sure you mean $cup_i(x_i)$, and not the ideal generated by the union (equivalently, by elements $x_i$? In both cases the statement is true, but from the given context I presume you mean the latter.
    $endgroup$
    – Wojowu
    Jan 25 at 9:34
















$begingroup$
Are you sure you mean $cup_i(x_i)$, and not the ideal generated by the union (equivalently, by elements $x_i$? In both cases the statement is true, but from the given context I presume you mean the latter.
$endgroup$
– Wojowu
Jan 25 at 9:34




$begingroup$
Are you sure you mean $cup_i(x_i)$, and not the ideal generated by the union (equivalently, by elements $x_i$? In both cases the statement is true, but from the given context I presume you mean the latter.
$endgroup$
– Wojowu
Jan 25 at 9:34










1 Answer
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$begingroup$

If $R = bigcup_i (x_i)$, then $1in (x_i)$ for some $i$, so one of the principal ideals must be $(1)=R$.






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    1 Answer
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    1 Answer
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    $begingroup$

    If $R = bigcup_i (x_i)$, then $1in (x_i)$ for some $i$, so one of the principal ideals must be $(1)=R$.






    share|cite|improve this answer









    $endgroup$


















      1












      $begingroup$

      If $R = bigcup_i (x_i)$, then $1in (x_i)$ for some $i$, so one of the principal ideals must be $(1)=R$.






      share|cite|improve this answer









      $endgroup$
















        1












        1








        1





        $begingroup$

        If $R = bigcup_i (x_i)$, then $1in (x_i)$ for some $i$, so one of the principal ideals must be $(1)=R$.






        share|cite|improve this answer









        $endgroup$



        If $R = bigcup_i (x_i)$, then $1in (x_i)$ for some $i$, so one of the principal ideals must be $(1)=R$.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 25 at 9:20









        SladeSlade

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