A graph is called almost self-complementary if it is isomorphic to one of its almost complements Xc - I, where Xc denotes the complement of X and I a perfect matching (1-factor) i...
The resonance graph R(B) of a benzenoid graph B has the perfect matchings of B as vertices, two perfect matchings being adjacent13 if their symmetric difference forms the edge set...
For an oriented graph G with n vertices, let f(G) denote the minimum number of transitive subtournaments that decompose G. We prove several results on f(G). In particular, if G is...
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...
The class composition C K of Boolean clones, being the set of composite functions f(g1, . . . , gn) with f C, g1, . . . , gn K, is investigated. This composition C K is either...