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1. • CommentRowNumber1.
   • CommentAuthorjesse
   • CommentTimeMar 8th 2017
   • (edited Mar 8th 2017)
   • PermaLink
   Author: jesse
   Format: MarkdownItexCreated [[Fraïssé limit]]. (I was pleasantly surprised to see @David_Corfield had [posted](https://golem.ph.utexas.edu/category/2009/11/fraisse_limits.html) about the these things a while ago for the n-Category Cafe.) Mentioned a neat result of Olivia Caramello's that [[omega-categorical]] structures presentable as Fraisse limits are determined by their automorphism groups $G$ with the topology of pointwise convergence in a very nice way: their [[classifying topos|classifying toposes]] are precisely the toposes of continuous $G$-sets. To fill in a grey link, I also created an entry for the [[countable random graph]].

   Created Fraïssé limit.

   (I was pleasantly surprised to see @David_Corfield had posted about the these things a while ago for the n-Category Cafe.)

   Mentioned a neat result of Olivia Caramello’s that omega-categorical structures presentable as Fraisse limits are determined by their automorphism groups $G$ with the topology of pointwise convergence in a very nice way: their classifying toposes are precisely the toposes of continuous $G$-sets.

   To fill in a grey link, I also created an entry for the countable random graph.

2. • CommentRowNumber2.
   • CommentAuthorDavid_Corfield
   • CommentTimeMar 8th 2017
   • PermaLink
   Author: David_Corfield
   Format: MarkdownItexI hope the discussion at the Cafe got things right in the end. I recall plenty of terminological confusion about what kind of limits and embeddings were involved. I see my [follow-up](https://golem.ph.utexas.edu/category/2010/01/looking_for_compatible_structu.html) didn't generate much discussion.

   I hope the discussion at the Cafe got things right in the end. I recall plenty of terminological confusion about what kind of limits and embeddings were involved.

   I see my follow-up didn’t generate much discussion.