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Idempotents in bicategories

Published online by Cambridge University Press:  17 April 2009

R. Paré ,
R. Rosebrugh  and
R.J. Wood
R. Paré
Affiliation:
Dept of Math, Stats and Comp Sci, Dalhousie University, Halifax, Nova Scotia Canada. B3H 3J5
R. Rosebrugh
Affiliation:
Department of Math and Computer Science, Mount Allison University, Sackville, New Brunswick E0A 3C0Canada.
R.J. Wood
Affiliation:
Dept of Math, Stats and Comp Sci, Dalhousie University, Halifax, Nova Scotia Canada. B3H 3J5
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Abstract

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It is shown that the category of fixed points of a left exact idempotent functor on a topos is again a topos. As well as a direct proof, a bicategorical proof is given which shows that the result only depends on certain bicategorical exactness properties.

Type
Research Article
Information
Bulletin of the Australian Mathematical Society , Volume 39 , Issue 3 , June 1989 , pp. 421 - 434
Copyright
Copyright © Australian Mathematical Society 1989

References

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