Talk:Chain duality III (Ex)
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Revision as of 12:34, 1 June 2012 by Martin Olbermann (Talk | contribs)
We check this for objects .
Let be an element of .
We have to check the equality of
and
This follows from the commutative diagram
as the first square commutes by naturality of and the second one by definition of a functor of categories with chain duality.