Dear Richard, Andrew Stacey asked a related question on the categories list in 2009: http://article.gmane.org/gmane.science.mathematics.categories/124 His summary of responses is here. http://article.gmane.org/gmane.science.mathematics.categories/140 All of the posts can be found at http://search.gmane.org/?query=bi-presheaves&group=gmane.science.mathematics.categories&sort=revdate Cheers, Simon. On 12/05/14 05:09, Richard Garner wrote:
Dear categorists,
One of the more folklorish constructions in category theory is that of the Isbell envelope. The folklorishness, in this case, seems to be so severe that I cannot find mention made of it in any published article at all (though there are several to the related notion of Isbell conjugacy). I am writing, therefore, in the hope that this is only due to my own poor knowledge of the literature, and that some other reader of this list may be able to put me to rights.
Richard
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