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Results tagged with gn.general-topology
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user 1784
Continuum theory, point-set topology, spaces with algebraic structure, foundations, dimension theory, local and global properties.
6
votes
When are there enough projective sheaves on a space X?
Searching for various examples and counterexamples for sheaves, it is sometimes helpful to look at partially ordered sets with the poset topology: a set $U$ is open if and only if $x \in U$ and $x < y …
- 13.1k
21
votes
Accepted
When are there enough projective sheaves on a space X?
About Jon Woolf's answer, it seems to me that the condition that "$x$ is a closed point" was implicitly used: the extension by zero $Z_A$ is only defined for a locally closed subset $A$ (see e.g. Tenn …
- 13.1k