29 Nov
2001
29 Nov
'01
10:58 a.m.
Al Vilcius asked:
If F:C-->C is a functor with opposite F*:C*-->C>* then (F-algebras)* is trivially equivalent to (F*)-coalgebras. Can this duality be induced by a schizophrenic object?
The answer is, in general, negative: every duality, where C has a terminal object, is of the above type, just take the constant functor of value 1. J. Adamek