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Subobject classifier -- Facts, Info, and Encyclopedia article (Site not responding. Last check: 2007-10-20) |
 | | In (Click link for more info and facts about category theory) category theory, a subobject classifier is a special object Ω of a category; intuitively, the subobjects of an object X correspond to the morphisms from X to Ω. |
 | | As an example, the set Ω = is a subobject classifier in the category of sets and functions: to every subset U of X we can assign the function from X to Ω that maps precisely the elements of U to 1 (see (Click link for more info and facts about characteristic function) characteristic function). |
 | | Every (A traditional theme or motif or literary convention) topos has a subobject classifier. |
| www.absoluteastronomy.com /encyclopedia/s/su/subobject_classifier.htm (337 words) |