Deducing Properties of Trees From Their Matula Numbers
Distance perfectness of graphs
In this paper, we propose a generalization of well known kinds of perfectness of graphs in terms of distances between vertices. We introduce generalizations of α-perfect, χ-perfect, strongly perfect graphs and we establish the relations between them. Moreover, we give sufficient conditions for graphs to be perfect in generalized sense. Other generalizations of perfectness are given in papers [3] and [7].
Distances between partially ordered sets
A distance between finite partially ordered sets is studied. It is a certain measure of the difference of their structure.