The intersection number of a digraph D is the minimum size of a set U, such that D is the
intersection digraph of ordered pairs of subsets of U. The paper describes much of the work …

We consider total digraphs of digraphs and present:(i) a structural characterization,(ii) an
algorithmic characterization based on a labeling procedure, and (iii) an efficient recognition …

A directed pathos block vertex digraph of an arborescence Ar, written Q= DPBV (Ar), is the
digraph whose vertex set V (Q)= V (Ar)∪ B (Ar)∪ P (Ar), where B (Ar) is the set of blocks …

Let D be a connected weighted digraph. The relation between the vertex-weighted
complexity (with a fixed root) of the line digraph of D and the edge-weighted complexity (with …

A directed pathos middle digraph of an arborescence A?, written Q= DPM (A?), is the
digraph whose vertex set V (Q)= V (A?)? A (A?)? P (A?), where V (A?) is the vertex set, A …