presheaf of a topological basis
Let be a topological space![]()
and let be a basis of its topology
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. We can regard as a category
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with objects being the open sets in and arrows/morphisms between to exists only if , andwhere the only element of is the injection map . Let now be a completecategory, we now define thepresheaf
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of -objects over the basis of the topology of to be a contravariant functor
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