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Elementary axioms for canonical points of toposes

Published online by Cambridge University Press:  12 March 2014

Colin McLarty*
Affiliation:
Department of Mathematics, Cleveland State University, Cleveland, Ohio 44115

Extract

Two elementary extensions of the topos axioms are given, each implying the topos has a local geometric morphism to a category of sets. The stronger one realizes sets as precisely the decidables of the topos, so there is a simple internal description of the range of validity of the law of excluded middle in the topos. It also has a natural geometric meaning. Models of the extensions in Grothendieck toposes are described.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1987

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References

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