Adam Jaffe, Department of Pure Mathematics, University of Waterloo
“Bipartite graphs admitting a k-NU polymorphism Part 3”
A k-ary polymorphism on a graph G = (V;E) is a map V k ! V that in some sense preserves the edge relation E. Such a polymorphism m is said to be near-unanimity (NU) if when at least k??1 of the inputs agree, then the value of m will be that near-unanimous input. Relational structures that admit an NU operation possess many nice properties. This seminar will provide a generating set for irre exive graphs which admit a k-NU polymorphism.