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Essential geometric morphisms between toposes over finite sets
Published online by Cambridge University Press: 24 October 2008
Extract
We show that if {Gi}J ε I is a generating set for an (elementary) topos ℰ then {P(Gi)}iεI is a cogenerating set for x2130;. From this we show that if topos ℰ contains an object G whose subobjects generate ℰ, then ΩG is a cogenerator for ℰ. Let denote the topos of finite sets and functions. We also show that if ℰ1 is a topos and ℰ2 is a bounded
-topos then every geometric morphism ℰ1 → ℰ2 is essential.
- Type
- Research Article
- Information
- Mathematical Proceedings of the Cambridge Philosophical Society , Volume 87 , Issue 1 , January 1980 , pp. 21 - 24
- Copyright
- Copyright © Cambridge Philosophical Society 1980
References
REFERENCES
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