Given a finite state machine M, a checking sequence is an input sequence that is guaranteed to lead to a failure if the implementation under test is faulty and has no more states t...
One class of Davenport-Schinzel sequences consists of finite sequences over n symbols without immediate repetitions and without any subsequence of the type abab. We present a bij...
Let n(G) denote the number of vertices of a graph G and let (G) be the independence number of G, the maximum number of pairwise nonadjacent vertices of G. The Hall ratio of a grap...
Let n be the fraction of structures of size" n which are connected"; e.g., a the fraction of labeled or unlabeled n-vertex graphshavingone component, b the fraction of p...
Jason P. Bell, Edward A. Bender, Peter J. Cameron,...
We prove that coloring a 3-uniform 2-colorable hypergraph with c colors is NP-hard for any constant c. The best known algorithm [20] colors such a graph using O(n1/5 ) colors. Our...