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Subject: question on functors adjoint to their dual
Date: Tue, 4 Feb 1997 13:29:21 -0400 (AST)
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Date: Tue, 4 Feb 1997 16:44:39 GMT
From: Hayo Thielecke <ht@dcs.ed.ac.uk>



I am interested in the following situation: a contravariant functor
adjoint to its own dual, with the unit and counit being the same
morphism, but _not_ an iso.

The canonical example is the contravariant internal hom on a cartesian
(or just symmetric monoidal) closed category, [(_) -> A] for some
object A.

My question is: is this typical, or are there (interesting) examples
of such adjunctions that do not come from exponentials?

Thanks,

Hayo Thielecke