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1. • CommentRowNumber1.
   • CommentAuthorUrs
   • CommentTimeMar 1st 2012
   • PermaLink
   Author: Urs
   Format: MarkdownItexstarted something at _[[topos of types]]_.

   started something at topos of types.

2. • CommentRowNumber2.
   • CommentAuthorMike Shulman
   • CommentTimeMar 1st 2012
   • PermaLink
   Author: Mike Shulman
   Format: MarkdownItexThat name seems a little unfortunate. It sounds to me like a topos built from type theory as a [[syntactic category]]. Where are the types in this construction? Also, what is a filter on a category?

   That name seems a little unfortunate. It sounds to me like a topos built from type theory as a syntactic category. Where are the types in this construction? Also, what is a filter on a category?

3. • CommentRowNumber3.
   • CommentAuthorUrs
   • CommentTimeMar 1st 2012
   • PermaLink
   Author: Urs
   Format: MarkdownItexYeah, I don't know. This terminology was invented by Makkai, and logicians around me stick to it. Could you maybe add a warning to the entry (I could add one, too, but I expect you can add a more informative one). The "category of filters" of a category $C$ that Makkai uses has as objects pairs consisting of an object $X$ of $C$ and a filter on $Sub_C(X)$.

   Yeah, I don’t know. This terminology was invented by Makkai, and logicians around me stick to it.

   Could you maybe add a warning to the entry (I could add one, too, but I expect you can add a more informative one).

   The “category of filters” of a category $C$ that Makkai uses has as objects pairs consisting of an object $X$ of $C$ and a filter on $Sub_C(X)$.

4. • CommentRowNumber4.
   • CommentAuthorMike Shulman
   • CommentTimeMar 1st 2012
   • PermaLink
   Author: Mike Shulman
   Format: MarkdownItexOk, I added a note, with a guess that it is a reference to "types" as used in model theory.

   Ok, I added a note, with a guess that it is a reference to “types” as used in model theory.