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Finite preorders and Topological descent I

✍ Scribed by George Janelidze; Manuela Sobral


Publisher
Elsevier Science
Year
2002
Tongue
English
Weight
178 KB
Volume
175
Category
Article
ISSN
0022-4049

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✦ Synopsis


It is shown that the descent constructions of ΓΏnite preorders provide a simple motivation for those of topological spaces, and new counter-examples to open problems in Topological descent theory are constructed.


πŸ“œ SIMILAR VOLUMES


Finite preorders and topological descent
✍ George Janelidze; Manuela Sobral πŸ“‚ Article πŸ“… 2002 πŸ› Elsevier Science 🌐 English βš– 92 KB

It is known that every e ective (global-) descent morphism of topological spaces is an e ective Γƒ etale-descent morphism. On the other hand, in the predecessor of this paper we gave examples of: β€’ a descent morphism that is not an e ective Γƒ etale-descent morphism; β€’ an e ective Γƒ etale-descent mo

Self complementary topologies and preord
✍ Jason I. Brown; Stephen Watson πŸ“‚ Article πŸ“… 1991 πŸ› Springer Netherlands 🌐 English βš– 709 KB

A topology on a set X is self complementary if there is a homeomorphic copy on the same set that is a complement in the lattice of topologies on X. The problem of characterizing finite self complementary topologies leads us to redefine the problem in terms of preorders (i.e. reflexive, transitive re