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Results tagged with ac.commutative-algebra
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user 13390
Commutative rings, modules, ideals, homological algebra, computational aspects, invariant theory, connections to algebraic geometry and combinatorics.
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Is it true that if $\operatorname{Ext}^{1}_{A}(P,A/I)=0 $ for all $ I$ then $P$ is projective?
It is well known that if $\mbox{Ext}^1_{A}(P,A/I)=0$ for all $I,$ then $\mbox{Ext}^i_{A}(P,A/I)=0$ for all $i$ and for all $I $and $P$ is projective.
We can also characterize a projective module $P$ …
