This paper shows that, given a factorization system, E/M on a closed symmetric monoidal category, the full subcategory of separated extensional objects of the Chu category is also star-autonomous under weaker conditions than had been given previously ([Barr, 1991]). In the process we find conditions under which the intersection of a full reflective subcategory and its coreflective dual in a Chu category is star-autonomous.
Theory and Applications of Categories, Vol. 4, 1998, No. 6, pp 137-147 http://www.tac.mta.ca/tac/volumes/1998/n6/n6.dvi http://www.tac.mta.ca/tac/volumes/1998/n6/n6.ps ftp://ftp.tac.mta.ca/pub/tac/html/volumes/1998/n6/n6.dvi ftp://ftp.tac.mta.ca/pub/tac/html/volumes/1998/n6/n6.ps