Combinatorial examples in universal coalgebra

Robert C. Davis
1983 Proceedings of the American Mathematical Society  
If an underlying-set functor different from the usual one is employed, the categories of multigraphs and of combinatorial systems become cotripleable over the category of sets. The category of multigraphs without loops and a common generalization are also examined.
doi:10.1090/s0002-9939-1983-0706504-6 fatcat:efccjxxlbfaltjxvhxosiztfka