The purpose of this note is to exhibit constructions which demonstrate that two problems dealing with self complementary graphs ~nd digraphs are polynomial time equivalent to graph isomorphism° The first problem is to decide whether a given graph or digraph is self complementary; this is a recognition problem. The second is to determine whether two self… (More)
In this paper we argue that natural language interfaces to databases should be able to produce summary responses as well as listing actual data. We describe a system (incorporating a number of heuristics and a knowledge base built on top of the database) that has been developed to generate such summary responses. It is largely domain-independent, has been… (More)
The number of colors needed to colour the blocks of a cyclic Steiner 2-design S(2, k, v) is at most v.