The paper generalizes the notion of a congruence on a category and pursues some of its applications. In particular, generalized congruences are used to provide a concrete construction of coequalizers in ${\cal C}at$. Extremal, regular and various other classes of epimorphic functors are characterized and inter-related.
Theory and Applications of Categories, Vol. 5, 1999, No. 11, pp 266-280 http://www.tac.mta.ca/tac/volumes/1999/n11/n11.dvi http://www.tac.mta.ca/tac/volumes/1999/n11/n11.ps ftp://ftp.tac.mta.ca/pub/tac/html/volumes/1999/n11/n11.dvi ftp://ftp.tac.mta.ca/pub/tac/html/volumes/1999/n11/n11.psTAC Home