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title = "Solutions to Set of all {Sets, Groups, Top. Spaces} does not exist"
author = "Yann Herklotz"
tags = []
categories = []
backlinks = ["4d"]
forwardlinks = ["4b", "4d2"]
zettelid = "4d1"
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The problem in Set Theory ([\#4b]) and the other spaces and collections,
is that one cannot build a collection of all collections. In Category
Theory, one has the same problem, not being able to have a Category of
all Categories. There are various possible solutions to this:
- Bound the size of objects by cardinal κ.
- Use Classes (from Set Theory: Sets that satisfy first order
formula).
- Grothendiek Universes (similar to bounding the size).
- Ignore the problem (possible for simple category theory).
[\#4b]: /zettel/4b
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