Re: Exact adjunctions

On Wed, Nov 21, 2001 at 10:27:06PM +0000, Dr. P.T. Johnstone wrote:

On Wed, 21 Nov 2001, Marco Grandis wrote:

I can't provide a reference for this result, but my ex-students will testify that it has been an exercise on the problem sets for my first-year graduate course in category theory for at least the last ten years. Also,

I so testify. Example sheet 2, question 3. As I recall, I couldn't do it at the time :-( Surprisingly, the result doesn't seem to be in CWM (Mac Lane). It is, however, in Lambek & Scott (Introduction to Higher Order Categorical Logic), in their brief introductory section. It is the content of Proposition 4.2 and Lemma 4.3, as far as I can see. Jules